OneClimateFuture_VulnerabilityAssessment_Final

scenarios. Based on both sets of flood risk data, sewer INFRASTRUCTURAL RISK
and stormwater infrastructure in Knightville, Ferry Village,
Simonton Cove, and Cushing Point face the greatest • Pearl Street Pump Station
vulnerability. In South Portland, the pipe network and • Willard Beach Pump Station
associated structures are dependent on each other for • “Industrial Area 1” Pump Station*
the operation of an efficient collection system, making it • “SMTC 1” Pump Station*
essential that vulnerable assets are managed proactively
and properly to prevent system failure. *as described in the GIS data provided

A) Pump Stations — Based on City GIS data, there are Figure 3.12 displays the pump stations that may be
34 pump stations in the City of South Portland. Figure affected by sea level rise. Five of South Portland’s pump
3.11 displays the pump stations that may be inundated by stations (approximately 15 percent) are predicted to be
the 1% annual chance flood. The Bay Road Pump Station impacted at 3.9 feet of sea level rise on top of the highest
and Loveitt’s Field Pump Station are located in the FEMA astronomical tide. These include:
VE flood zone. These pump stations are connected to
sewer and stormwater pipes also vulnerable to flooding • Pearl Street Pump Station
in this area near Willard Beach. Four additional pump • Elm Street Pump Station
stations are located in the AE flood zone: • Front Street Pump Station
• “Industrial Area 1” Pump Station*
• “Industrial Area 2” Pump Station*

*as described in the GIS data provided

South Portland Pump Stations Vulnerable to the 1% Annual Chance Flood

Figure 3.11. Pump stations in South Portland that are vulnerable to the 1% annual chance flood. Data from the City of South Portland and
FEMA preliminary flood zones (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 50

INFRASTRUCTURAL RISK

South Portland Pump Stations Vulnerable to Sea Level Rise

Figure 3.12. Pump stations in South Portland that are vulnerable to sea level rise based on four sea level rise scenarios for 2100. Data from the
City of South Portland and Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).

South Portland WWTF Flood Vulnerability

Figure 3.13. Extent of vulnerability of the wastewater treatment facility in South Portland to flooding from four scenarios of sea level rise
(left) and the 1% annual chance flood (right). Data from FEMA preliminary flood zones (2018) and Maine Geological Survey Sea Level Rise/
Storm Surge Scenarios (2018).
ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 51

B) Wastewater Treatment Facility — The South INFRASTRUCTURAL RISK
Portland wastewater treatment plant is currently
technically outside the 1% annual chance flood FEMA A flood zone. Primary areas that are projected to
zone; however, the site is projected to be partially be affected include Ferry Village, Simonton Cove, and
or fully inundated by sea level rise by 2100 under an Cushing Point.
Intermediate-High or High scenario, respectively (Figure
3.13). The facility could experience structural damage Only 2 percent of stormwater and sewer manholes in
or failure due to loads from wave action and water South Portland are vulnerable to 3.9 feet of sea level
inundation, impact from moving debris in a violent flood, rise on top of the highest astronomical tide; however,
or corrosion from salt exposure. this vulnerability increases to over 10 percent under
the HAT + 8.8-ft scenario. Highly impacted areas in
C) Manholes — Approximately 95 stormwater and South Portland include Knightville, Trout Brook south of
sewer manholes are exposed to high flood risk based on Meetinghouse Hill, Cushing Point, and Simonton Cove.
the 1% annual chance flood. Approximately 28 manholes
(less than 1 percent of all manholes in South Portland) D) Pipe Network — Approximately 21,822 linear feet
are located within the FEMA VE flood zone; 65 manholes of pipe in the South Portland sewer/stormwater pipe
(approximately 1 percent) are located within the FEMA network are exposed to high flood risk based on the
AE flood zone; and two manholes are located in the 1% annual chance flood (Figure 3.14). Of that total,
roughly 4,510 linear feet (less that 1 percent) of the pipe
network are in the VE flood zone; 16,310 linear feet are in

South Portland Pipe Network Vulnerability to the 1% Annual Chance Flood

Figure 3.14. Pipe network segments in South Portland that are vulnerable to the 1% annual chance flood. Data from the City of South
Portland and FEMA preliminary flood zones (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 52

the AE flood zone (approximately 3 percent of the pipe INFRASTRUCTURAL RISK
network); and roughly 1,002 linear feet are in the A flood
zone (less than 1 percent of the pipe network). Areas of locations in South Portland are predicted to be impacted
vulnerable pipe network are primarily along the coast and by flooding from the 1% annual chance flood. Of the
Fore River shoreline, Long Creek, and Trout Brook. six CSO sites, one is vulnerable to sea level rise based
on the HAT + 3.9 feet scenario. This impacted CSO site
At a sea level rise scenario of HAT + 3.9 feet, is located in Ferry Village. In total, there could be four
approximately 4 percent of the overall South Portland active CSO sites impacted under 8.8 feet of sea level rise
pipe network will be vulnerable to inundation. The high- on top of the highest astronomical tide. See Figure 3.15
risk areas include Knightville, Ferry Village, Cushing Point, for locations of the four impacted CSOs.
and Simonton Cove. In addition to the inundation of pipe
networks from flooding, pipes will be increasingly subject High Priority Areas
to structural damage by more intense freeze-thaw cycles Through this evaluation, the areas included in Figure 3.16
and increased groundwater salinity. were identified as high priority vulnerable areas. Table
3.8 summarizes areas of Portland and South Portland’s
E) Combined Sewer Overflows (CSOs) — Based on wastewater system that will be impacted by the 1%
the flood risk assessment, none of the six existing CSO annual chance flood and/or the sea level rise scenarios
that were discussed in this section. These areas are
labeled in Figure 3.16 .

South Portland CSO Sites Vulnerable to Sea Level Rise

Figure 3.15. CSO locations in South Portland that are vulnerable to flooding based on four sea level rise scenarios. Data from the City of
South Portland and Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 53

INFRASTRUCTURAL RISK

Wastewater Infrastructure Impact Summary by Area

Area City Pump CSO Manholes Pipe WWTF
Station(s) Site(s) X
Back Cove Portland X Network
Bayside Portland X X X X
East End Portland X X X
Riverton Portland X X
Peaks Island Portland X X
Commercial Street Portland X XX
Stroudwater Portland X X
Simonton Cove South Portland X XX
Ferry Village South Portland X X
Cushing Point South Portland X X
Knightville South Portland X XX
Turner Island South Portland X XX
X X

Table 3.8. Summary of affected infrastructure in high priority areas in Portland and South Portland that have large numbers of stormwater
and sewer infrastructure assets vulnerable to the 1% annual chance flood and/or sea level rise.

Reference Map for High Priority Areas in Table 3.8

RIVERTON

CK COVE
BA
COMMERCIAL ST>BAYSIDEEAST
END

STROUDWATER PEAKS
ISLAND

CUSHING
PT.

FERRY SIMONTON
VIL. COVE

KNIGHTVILLE
TURNER

ISL.

Figure 3.16. High priority areas in Portland and South Portland that have large numbers of stormwater and sewer infrastructure assets
vulnerable to the 1% annual chance flood and/or sea level rise.

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INFRASTRUCTURAL RISK

3.3 Transportation Bike and Pedestrian — Networks of bike lanes, shared
use pathways, neighborhood byways, sidewalks, and trails
Infrastructure
INTERSTATES AND ROADWAYS
Portland and South Portland are fortunate to have a Activity in Portland and South Portland relies on
multi-modal transportation network serving residents, extensive road networks, including interstates, arterials,
businesses, visitors, and key economic sectors. The collectors, and local roads. Arterials are high-capacity
various transportation systems are designed to consider roads that transport traffic between major destinations
some weather interruptions; however, climate change and to interstates or highways. A collector road connects
is expected to increase the frequency, intensity, and traffic between local and arterial roads. Local roads
duration of the extreme weather events, while also are the most common; they have high accessibility to
causing long-lasting change to the cities through sea abutting land uses and connect to collector and arterial
level rise. Transportation infrastructure may face acute roads. Obstructions or closures will create different types
or chronic damage, disruption, or delay, or complete of vulnerabilities depending on the road type. Closures
long-term loss of capacity depending on location. or obstructions of arterial roads could be considered
Adaptation will be necessary to ensure the ongoing more acute—they would quickly affect a larger number
reliability, safety, and efficiency of the local and regional of people and make evacuation more difficult during
transportation system. Major transportation assets in the emergency situations. Impacts to collector and local
two communities include: roads, however, would affect the ability of drivers to
access specific areas, business, and services.
Roads — Interstate highways I-95 and I-295; US Routes 1
and 302; State and local roadway networks Assessment of Highway Corridor Priority Areas
As part of the Maine DOT highway asset management
Air — Portland International Jetport (passenger and program, highway assets are categorized into six levels
freight) known as Highway Corridor Priorities (HCP), used
for monitoring roadway conditions and prioritizing
Rail — Pan Am Railways, St. Lawrence and Atlantic investment. Highway Corridor Priorities were set by
Railroad Co. (freight rail); Turner Island LLC (freight Maine DOT based on several factors including the
terminal and switching); Amtrak Downeaster (passenger function of the roadway and its contribution to the
rail); Portland Transportation Center (passenger train overall economic health of the state. This assessment
and bus station) looks at the flood vulnerability of HCP categories 1
through 4 as a means for understanding the climate
Bus — Greater Portland Transit District METRO vulnerability of the major road networks in Portland and
(local bus service); South Portland Bus Service (local South Portland. Categories 1 through 4 are defined as:
bus service); Shuttlebus-Zoom (local bus service);
Lakes Region Explorer and Paratransit (local bus • Priority 1 – Includes the Maine Turnpike, interstate
service); Concord Coach Lines (regional bus service);
Greyhound Bus Lines (regional bus services); Portland system, and key principal arterials
Transportation Center (passenger train and bus station);
Greyhound Bus Station (passenger bus station); South • Priority 2 – High-value arterials
Portland Bus Transit Hub (passenger bus station) • Priority 3 – Remaining arterials and significant major

Marine — Casco Bay Lines (passengers and freight ferry collector highways
service); Portland OceanTerminal (passenger and freight
ferry terminal); Ocean Gateway Terminal (international • Priority 4 – Remaining major collector highways, and
ferry and cruise ship terminal); International Marine
Terminal (international marine freight terminal); Merrill minor collector highways
Marine Terminal (private marine freight terminal); Many
private petroleum storage and distribution terminals

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 55

As outlined in the Introduction of the Infrastructure INFRASTRUCTURAL RISK
Section, two sets of flood risk data were used in this
analysis, which provide complementary assessments of sea level rise under the Intermediate scenario, or 3.38
flood risk. The first investigation looks at FEMA Flood feet under the Extreme scenario specifically for the
Rate Insurances Maps (FIRMs), which depict areas that Greater Portland area. (See page 35 for further details.)
are vulnerable to inundation by the 1% annual chance The Maine DOT data for High Corridor Priorities were
flood. (See page 35 for descriptions of the flood zone updated as of July 2019.
designations.) The second investigation uses geospatial
data from the Maine Geological Survey, which shows Portland — HCP roadways in the vicinity of Back Cove
relative levels of inundation from sea level rise or storm that may be impacted by the current 1% annual chance
surge for the Maine coast for the year 2100 under six flood include Route 1 at Martin's Point (priority 3),
scenarios. The specific scenarios selected for this analysis and Baxter Boulevard on the north side of Back Cove
include 1.6, 3.9, 6.1 and 8.8 feet of sea level rise on top of (priority 4) (Figure 3.17). Although I-295 crosses an AE
the highest astronomical tide (HAT), which correspond flood zone north of Back Cove and a VE flood zone at
to the Low-Intermediate, Intermediate, Intermediate- Tukey's bridge, the FEMA maps suggest that the roads
High and High scenarios for 2100, respectively. By 2050, are elevated enough in both locations so as not to be
we would expect to already see 1.48 feet of relative affected. Other HCP roadways in Portland that may be
affected by the 1% annual chance flood include Congress
Street (priority 2) where the route crosses the Fore

Highway Corridor Priority Roadways and FEMA Flood Zones – Back Cove

BAXTER BLVD
TUKEY'S BRG

RTE 1

I-295

Figure 3.17. Highway Corridor Priority (HCP) areas in Portland’s Back Cove overlaid with FEMA flood zones for the 1% annual chance
flood. HCP roadways in the Back Cove vicinity that may be impacted include Route 1 at Martin's Point (priority 3), and Baxter Boulevard
on the north side of Back Cove (priority 4). Data from Maine DOT and FEMA preliminary flood zones (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 56

River, as well as potentially a couple small pinch points INFRASTRUCTURAL RISK
on Brighton Ave (priority 2) and Capisic Street (priority
4) where the routes cross the Capisic Brook and Capisic if sea levels reach 8.8 feet above the astronomical high
Pond, respectively. However, culverts in both locations tide—most critically I-295 (priority 1), as well as Fore
may prove sufficient. River Parkway and Washington Ave (priority 2) (Figures
3.18 and 3.19). Interstate and high-value arterials tend
With sea level rise up to 3.9 feet above the highest to accumulate higher volumes of traffic on a daily basis
astronomical tide (HAT), the highest priority roads in and provide more direct routes for drivers, which makes
Portland that are expected to be affected include I-295 closures on these routes most problematic.
exits 7 and 6A (priority 1); Franklin Street, State Street,
High Street, Commercial Street, and Congress Street South Portland — Based on the information available
where it crosses the Fore River (priority 2); Marginal Way, in the assessment, no High Corridor Priority roadways in
Preble Street, and Elm Street (priority 3); and Baxter South Portland are vulnerable to the 1% annual chance
Boulevard and Forest Ave (priority 4). A number of flood. HCP roadways also show very little vulnerability to
additional priority roads would be potentially inundated inundation up through 3.9 feet of sea level rise on top of
the astronomical high tide. Broadway where the route
crosses Anthoine Creek and the Mill River (priority 2)

Highway Corridor Priority Areas Vulnerable to Sea Level Rise – Back Cove

WASHINGTON AVE TUKEY'S BRG
RTE 1

I-295FRANKLIN ST.
STATE ST
Figure 3.18. Highway Corridor Priority (HCP) areas in Portland’s Back Cove area that are vulnerable to flooding based on four sea level rise
scenarios. Data from Maine DOT (HCP areas) and Maine Geological Survey (sea level rise inundation).
ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 57

INFRASTRUCTURAL RISKFRANKLIN ST.
STATE ST
Highway Corridor Priority Areas Vulnerable to Sea Level Rise – Commercial Street

I-295

COMMERCIAL ST

* NOTE: Bridges were removed in LIDAR data. Sea level rise inundation areas
show areas under the bridges, not inundation of the bridges themselves.

Figure 3.19. Highway Corridor Priority (HCP) areas in Portland’s Commercial Street area that are vulnerable to flooding based on four sea
level rise scenarios. Data from Maine DOT and Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).

Portland Highway Corridor Priority Roadways Impacted by Sea Level Rise

Road Segment Ranking Area Note

I-295 Priority 1 Back Cove I-295 is a major highway corridor through the City of Portland and heavily traveled.
Back Cove The roadway provides access to and from the City of Portland.
Franklin Street Priority 2 Back Cove Franklin Street connects I-295 and the waterfront, and provides access to downtown.
Back Cove Washington Ave provides access to the northwest side of the city (East and North
Washington Ave Priority 2 Back Cove Deering), and connections between I-295 and areas to access I-95.
Back Cove The State Street / High Street / Forest Ave intersection provides access to and from
State Street / High Priority 2 Back Cove I-295 and to the waterfront through downtown Portland.
Street / Forest Ave Waterfront Marginal Way parallels I-295, provides access to a number of the highway on-ramps,
Waterfront as well as area businesses.
Marginal Way Priority 3 Preble Street / Elm Street provide connections between Back Cove / Baxter
Boulevard and downtown Portland.
Preble Street / Elm Priority 3 Baxter Boulevard is a frequently used scenic roadway that provides access between
Street the downtown peninsula and western portions of the city.
Commercial Street is the main roadway serving the waterfront.
Baxter Boulevard Priority 4
Fore River Parkway provides direct access to the downtown area of the city as well as
Commercial Priority 2 the Casco Bay Bridge which serves South Portland.
Street Priority 2
Fore River
Parkway

Table 3.9. Maine Department of Transportation Highway Corridor Priority (HCP) Roadways (priority categories 1-4) in the City of Portland
that are projected to be impacted by sea level rise based on four sea level rise scenarios for 2100.

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 58

INFRASTRUCTURAL RISK

Highway Corridor Priority Areas Vulnerable to Sea Level Rise – Knightville and Ferry Village

BREAKWATER DR
BROADWAY

MARKET ST COTTAGE RD

BROADWAY
* NOTE: Bridges were removed in LIDAR data. Sea level rise inundation areas
show areas under the bridges, not inundation of the bridges themselves.

Figure 3.20. Highway Corridor Priority (HCP) areas in South Portland’s Knightville and Ferry Village neighborhoods that are vulnerable to
flooding based on four sea level rise scenarios. Data from Maine DOT and Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).

South Portland Highway Corridor Priority Roadways Impacted by Sea Level Rise

Road Segment Ranking Area Note

Casco Bay Bridge Priority 2 Knightville The impacts will be to the roadway from Casco Bay Bridge as it turns into Broadway,
or the approach to the bridge, not to the actual Casco Bay Bridge roadway itself.
Broadway Priority 2 Knightville Broadway in Knightville is a heavily traveled roadway that provides access to Casco
Bay Bridge, the Mill Creek shopping area and the wastewater treatment plant.
Broadway Priority 3 Ferry Village Broadway in Ferry Village provides access to residential, recreation, marina,
commercial, retail, restaurant, and industrial uses.
Waterman Drive Priority 4 Knightville Waterman Drive provides access to the wastewater treatment plant, Thomas Knight
Park, and South Port Marine. This area of the city also has residential, commercial,
Ocean Street Priority 4 Knightville restaurant, and retail uses.
Hinckley Drive & Priority 4 Knightville Ocean Street provides access to residential, commercial, and retail uses.
Market Street Hinkley Drive / Market Street provide access between Cottage Road and Waterman
Priority 4 Knightville Drive through the Mill Creek shopping area.
Cottage Road Cottage Road provides access to the Mill Creek shopping area and connector roads
Knightville to the wastewater treatment plant.
Highland Avenue Priority 4 Ferry Village Highland Avenue provides a connection to and from South Portland to roadways
Ferry Village leading to Cape Elizabeth and residential neighborhoods in South Portland.
Henley Street Priority 4 Henley Street provides local access to the Portland Pipeline and Gulf Oil terminals.
Preble Street Priority 4 Preble Street provides local access to the Portland Pipeline and Gulf Oil terminals.

Table 3.10. Maine Department of Transportation Highway Corridor Priority (HCP) Roadways (priority categories 1-4) in the City of South
Portland that are projected to be impacted by sea level rise based on four sea level rise scenarios for 2100.

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 59

show potential vulnerable pinch points. With sea level INFRASTRUCTURAL RISK
rise up to 8.8 feet on top of the highest astronomical
tide (HAT), affected HCP roadways in South Portland segments; therefore, the maps show segments in which
include Broadway near Knightville and at the junction at least a portion of the segment is impacted by flooding.
to the Casco Bay Bridge (priority 2); Broadway at Ferry
Village (priority 3); as well as Waterman Drive, Ocean As used in the analysis of HCP roadways, flood risk was
Street, Market Street, Cottage Road (in Knightville), and assessed using both the preliminary FEMA flood zone
Preble Street (in Ferry Village) (priority 4). This level data (2018) for the 1% annual chance flood and Maine
of inundation cuts off access to the City's wastewater Geological Survey data (2018) for four sea level rise
treatment plant (via Waterman Drive) (Table 3.10). scenarios for 2100 (Low-Intermediate, Intermediate,
Intermediate-High and High scenarios).
Annual Average Daily Traffic
Further evaluation of roadway vulnerability for Portland High-Volume Roadways Vulnerable to Inundation
and South Portland was completed through the review from Sea Level Rise in Portland
of annual average daily traffic (AADT) data collected by
Maine DOT. AADT is the accumulation of daily traffic Road Type Miles % of Total Miles
volume measurements over the course a year, then
divided by 365 to calculate an average per day. The use Interstate Impacted (AADT >5000)
of AADT data is a best practice for determining the Major Collector
volume of traffic a road experiences and how it should be Minor Arterial HAT + 1.6 Feet
planned for, designed, or maintained. Local
Other 0.0 0.0
This assessment was completed to understand which
high-volume roadways are vulnerable to flooding. Interstate 0.0 0.0
There is no specific threshold by which roadways are Major Collector
categorized as either low-volume or high-volume; this Minor Arterial 0.1 0.3%
cutoff varies state-to-state. Based on the AADT data for Local
Portland and South Portland, it was determined that any Other 0.1 0.3%
road with an AADT equal to or greater than 5,000 would
be assessed for flood risk to determine high-volume Interstate 0.0 0.0
roadways of concern. AADT data is based on road Major Collector
Minor Arterial HAT + 3.9 Feet
Local
Other 0.3 0.7%

Interstate 0.1 0.2%
Major Collector
Minor Arterial 0.1 0.3%
Local
Other 0.1 0.3%

0.0 0.0

HAT + 6.1 Feet

2.8 7.3%

0.9 2.3%

High-Volume Roadways Vulnerable to the 1% Annual 1.7 4.4%
Chance Flood in Portland
0.2 0.5%

Miles % of Total Miles 0.1 0.3%
Impacted (AADT >5000)
Road Type HAT + 8.8 Feet
2.11 5.6%
Interstate 0.95 2.5% 3.2 8.5%
Major Collector 0.30 0.8%
Minor Arterial 0.0 0.0 1.0 2.8%
Local 0.33 0.9%
Other 2.1 5.5%

0.2 0.5%

0.1 0.4%

Table 3.11. Extent of high-volume roadways (annual average daily Table 3.12. Extent of high-volume roadways (annual average daily
traffic greater than 5,000) in FEMA A, AE, and VE flood zones in traffic greater than 5,000) in Portland that are vulnerable to sea
Portland. All zones represent vulnerability to the 1% annual chance level rise based on four sea level rise scenarios on top of the
flood. astronomical high tide (HAT).

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INFRASTRUCTURAL RISK

Portland — Overall, there are five segments of The areas affected will likely cause bottlenecks and
Interstate and two segments of Major Collector roadways access issues in the roadway system. Roadways affected
in coastal Portland, and several inland road segments, by the various sea level rise scenarios are presented in
where some of the roadway is located in FEMA flood Table 3.14. No high-volume roadways will be impacted by
zones (Figure 3.21). The impacted roadways surrounding the 1.6-ft and 3.9-ft sea level rise scenarios.
Back Cove are considered high-risk areas due to high
traffic volumes. Table 3.11 details the percentage of the High-Volume Roadways Vulnerable to Inundation
heavily traveled roadways in Portland that are in any from Sea Level Rise in South Portland
designated flood zone along with estimated AADT.
Road Type Miles % of Total Miles
Sea level rise will further amplify the flooding (AADT >5000)
experienced during the 1% annual chance storm (Figure Interstate Impacted
3.22). A significant number of road segments are Major Collector HAT + 1.6 Feet 0.0
projected to be inundated at the highest astronomical Minor Arterial 0.0
tide under 1.6 feet of sea level rise, a level that is possible Local 0.0 0.0
for 2050. Results for each sea level rise scenario are Other 0.0 0.0
presented in Table 3.12. Overall, areas of most concern 0.0 0.0
include Back Cove, Bayside, and Commercial Street. Interstate 0.0
Major Collector 0.0 0.0
South Portland — The City of South Portland has Minor Arterial 0.0
minimal flooding impacts to high-volume roadways Local HAT + 3.9 Feet 0.0
within the city boundary under the 1% annual chance Other 0.0
flood (Table 3.13 and Figure 3.23). The areas affected by 0.0 0.0
flooding are somewhat dispersed, but primarily located Interstate
along Trout Brook and Anthoine Creek. Major Collector 0.0 0.0
Minor Arterial 1.5%
Sea level rise will create further flood impacts on heavily Local 0.0 1.1%
traveled roadways in South Portland. There are six Other 0.0
primary focus areas: the I-295 bridge crossing, Veterans 0.0 0.0
Memorial Bridge, Pleasantdale, Knightville, Ferry Village, Interstate
and Simonton Cove/Willard’s Beach area (Figure 3.24). Major Collector 0.0 0.0
Minor Arterial 2.1%
High-Volume Roadways Vulnerable to the 1% Annual Local HAT + 6.1 Feet 1.9%
Chance Flood in South Portland Other 0.0 0.2%
0.3 0.0
Road Type Miles % of Total Miles 0.2
Impacted (AADT >5000) 0.0
Interstate 0
Major Collector 1.34 1.2%
Minor Arterial 0.33 0.2% HAT + 8.8 Feet
Local 0.87 0.2% 0.0
Other 0.00 0.0 0.5
0.95 0.3% 0.4
0.04
0.0

Table 3.13. Extent of high-volume roadways (annual average daily Table 3.14. Extent of high-volume roadways (annual average daily
traffic greater than 5,000) in FEMA A, AE, and VE flood zones in traffic greater than 5,000) in South Portland that are vulnerable to
South Portland. All zones represent vulnerability to the 1% annual sea level rise based on four sea level rise scenarios on top of the
chance flood. astronomical high tide (HAT).

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INFRASTRUCTURAL RISK

Portland High-Volume Roadways Vulnerable to the 1% Annual Chance Flood

Figure 3.21. High-volume roadways (annual average daily traffic greater than 5,000) in Portland that are vulnerable to flooding from the 1%
annual chance flood. Data from Maine DOT and FEMA preliminary flood zones (2018).

Portland High-Volume Roadways Vulnerable to Flooding from Sea Level Rise

Figure 3.22. High-volume roadways (annual average daily traffic greater than 5,000) in Portland that are vulnerable to flooding based on four
sea level rise scenarios. Data from Maine DOT and Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).
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INFRASTRUCTURAL RISK

South Portland High-Volume Roadways Vulnerable to the 1% Annual Chance Flood

Figure 3.23. High-volume roadways (annual average daily traffic greater than 5,000) in South Portland that are vulnerable to flooding from
the 1% annual chance flood. Data from Maine DOT and FEMA preliminary flood zones (2018).

South Portland High-Volume Roadways Vulnerable to Flooding from Sea Level Rise

Figure 3.24. High-volume roadways (annual average daily traffic greater than 5,000) in Portland that are vulnerable to flooding based on four
sea level rise scenarios. Data from Maine DOT and Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).
ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 63

INFRASTRUCTURAL RISK

AIR TRANSPORTATION INFRASTRUCTURE BUS TRANSPORTATION INFRASTRUCTURE
The Portland International Jetport is a small commercial The Greater Portland METRO Bus Service and
airport located near the Fore River in Portland and South South Portland Bus Service may experience service
Portland. The Jetport has two intersecting runways and interruptions during severe storms or a flooding event,
a passenger terminal, and accommodates shipping goods depending on bus routes. Regional bus systems that
by air such as freight and mail. Only a portion of the have bus depots in Portland are Concord Coach, which
Jetport’s property adjacent to the Fore River is located in is located at the Portland Transportation Center on
a FEMA 1% annual chance flood zone (Figure 3.25) and Thompson’s Point, and Greyhound, which is located
sea level rise is not anticipated to have direct impacts at the corner of Congress Street and St. John Street.
on the runways or passenger terminal. The roadway that Neither of these stations are in the FEMA 1% annual
serves the airport may be impacted near the Stroudwater chance flood zones or are projected to be impacted by
area portion of Congress Street. Alternate routes, sea level rise. Although stations are “fixed nodes” in a
however, would be available. Potential other climate- bus system, routes will likely change over time based
related impacts to the Jetport may include schedule on demand and other factors, which also means bus
disruptions or increased turbulence due to severe storm networks will have a level of adaptability to adjust their
events or wind pattern changes. routes to contend with the effects of climate change.

Portland International Jetport and FEMA Flood Zones

Figure 3.25. Portland International Jetport overlaid with FEMA flood zone data. Neither the passenger terminal nor the runways show
vulnerability to the 1% annual chance flood. Data from FEMA preliminary flood zones (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 64

MARINE TRANSPORTATION INFRASTRUCTURE INFRASTRUCTURAL RISK
The Portland Ferry Terminal, Ocean Gateway Terminal,
International Marine Terminal, and Merrill Marine both new opportunities and risks for shipping transport
Terminal support a mix of passenger and/or freight into the Port of Portland.
transit services. The Portland Ferry and Ocean Gateway
terminals are located in the FEMA 1% annual chance RAIL TRANSPORTATION INFRASTRUCTURE
flood zone and all four terminals are projected to see The freight and passenger rail services in the Greater
impacts from sea level rise, which could alter how these Portland area serve as important transportation
services are offered in the future or require relocation or connections throughout Maine and New England.
significant upgrades to the docks and terminal buildings. Greater Portland has three major freight rail operators:

This marine infrastructure provides a link to land-based • Pan Am Railways – This operator runs a line from
infrastructure systems for passengers and the movement
of goods. Therefore, without re-engineering these South Berwick, ME through Portland into Penobscot
connections across the waterfront, the link to associated County and is a primary connection to the rest of
parking, trucking, or rail systems would also remain the country.
vulnerable. Direct rail connections for moving bulk
cargo and container freight are particularly important • St. Lawrence & Atlantic Railroad Co. – This operator
for the Merrill Marine Terminal (near Veterans Memorial
Bridge) and the International Marine Terminal (adjacent runs a line from Portland north to Montreal.
to the Casco Bay Bridge). In addition to the marine
transportation assets listed above, private shipping • Turners Island LLC – This is a terminal operator
terminals in the two cities, and in particular many of the
South Portland terminals associated with petroleum connecting Pan Am to the shipping facility in South
storage and transport, are likewise vulnerable to sea Portland.
level rise and storm surge. (See sections 3.1 Energy
Infrastructure and 3.5 Impacts to Sites of Contaminated In addition to freight rail lines, the Downeaster passenger
Soil and Hazardous Waste Containment for further rail travels a route covering 143 miles between Boston
details.) Extreme weather and flooding may increasingly and Brunswick, ME, and makes round trips from Portland
have the following impacts: to Boston numerous times per day.

• Interruptions or temporary closures in operations; Railways generally are sensitive to extreme weather.
• Damage to property (docks, wharves), cargo Flooding and heavy precipitation can accelerate wear
on rail lines and cause erosion resulting in instability
(containers), or equipment; around rail tracks. Steel tracks are designed to operate
in a narrow range of temperatures, based on the climate
• Increased costs from maintenance or repair; where (and when) the track was originally installed.
• Need for reconfiguration of operational areas (cargo Temperatures significantly above the optimal operating
temperature can cause the metal to expand and buckle,
storage, docks, berths, piers, etc.); creating what are called “sun kinks.” More days of
extreme heat increase the chance of rail line failure,
• Increased corrosion or oxidation of equipment, and train travel must be reduced or put on hold until
temperatures drop to reduce stress on the tracks. Recent
tanks, and pipelines; and studies estimate that these delays will have significant
economic repercussions throughout the United States,
• Spills or accidents that could discharge pollutants including for routes in Maine.83

into Casco Bay. The rail lines serving Portland and South Portland also
have portions of their tracks located in FEMA flood
For all marine transportation infrastructure, extreme zones and areas that may be impacted by sea level rise.
weather may affect shipping conditions, creating These conditions have and will cause infrastructure
greater hazards to navigation, ship, cargo, and crew damage, service disruption, and wide scale ripple effects
that could also alter the way these facilities operate. in rail transit. Figure 3.26 displays the active rail lines in
Rising temperatures in the Arctic are likely to make new Portland and South Portland, overlaid with the FEMA
shipping lanes increasingly navigable, which may create flood zones and the sea level rise scenarios.

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 65

Active Rail Lines in Portland and South Portland Vulnerable to the 1% Annual INFRASTRUCTURAL RISK
Chance Flood (top) and to Sea Level Rise (bottom)
Figure 3.26. Active rail lines in
Portland and South Portland
that are vulnerable to flooding
from the 1% annual chance
flood (top), and vulnerable
to flooding based on four sea
level rise scenarios (bottom).
Data from Maine DOT, FEMA
preliminary flood zones (2018),
and Maine Geological Survey
Sea Level Rise/Storm Surge
Scenarios (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 66

INFRASTRUCTURE IS CRITICAL TO While some types of infrastructure are routinely upgraded and replaced,
DEVELOPMENT PROGRAMS
bmuailjdoirnignsf—rasatrreucstigunreificparnotjeinctvse—stmsuecnhtsasthbartidcgaens,tsaeIkNweFemRraAsnySysTtyeRemUaCrs,sTatUnodRpAplaLunbRlaIicSnKd
Development programs and priorities often rely on highly functioning
infrastructure to deliver services to those in need and achieve program build. Once constructed, these systems are often in service for decades
and frequently guide local and regional development patterns. As a
3.4 Communicationobjectives.While infrastructure may not always be a central component,
reTsualbtl,eth3e.1i5nfsruamstmruacrtuizreesdtehceispioontesnmtiaadl eimtpoadcatysmclaimy aatfefect several
support for infrastructure development and maintenance is woven gethcecIeonnhyneaporrneaampgrtitriecoeicsawnuensinld.laltBrsi,mneotcccahairjaoeuelrsaDvefsiitHiniannalSifgntrylaCcysioalthirlfmuacccvoaotemtmuerommeCniutahmnInCaidtenTientgshtiesneafaiRnrrndeasdesscirtiolnrvieufuilcnnucetectsrnuyieacrrseee—.dinaetnveedglorbapelmctaoeuntshtee
paAttsesrensss—miteinstcfroitircaCl athsactothBeayyahreigdhelisgighnteeddatnhdemriasikntoafinseedvteorebe low-
Systems Infrastructurethroughout many development programs. Infrastructure plays an casrtboornm, rseswiliietnht,haingdhrwesipnodnssdivaemtoagthinegimcepallcutlsarofacnlidmmateiccrhoawnagveeover
mptimlaetsoonuqernewr.ugiInnieimpegrg,mspaea,onnenhdrenditrgatdas,hnele,atestaniirhgtdenltiesefl(volmtFoeoniglopguirnedericrserioneat1hrgtdp)ue.forrraoeronawstmtieacnifiphcnflaeeigmtcaentavdityenestgpewcrrhevoealiecrcnkecigptecliritfaoceabontonliieofcssiindno,efrsrratasottirorumncstuinrteo, the
integral role in achieving core purposes in programs such as Feed Inoatdhdeitrioenq, muiupcmh eonf tin.8f4rastructure is interdependent. For example,

ttrhaedFeu; dtuiIsnraefsot(eFrrTmrFai)s;tkwioraentdeaur,ncstdaionCnit;oaatmniodmn,uuarnbndaicnhadytgieoivenenlseo;Tpeemccoehnnnot.omFlooicrggeyrxo(awImCtTphl)ean, d power stations provide energy to help telecommunications systems
by suppsoyrstitnegmcsoninstcrluucdtieonceolfl wtoawteerrisnfaransdtrufacctuilrieti,eUs,SfAibIDeralnindeost,her
developtmeelenpthporancetitnioentewros rpkrso,vdidaetapocteanbtleerwsa, taenrdtoocthoemrmruenlaittiesd tfuhTnisc,htaeiodrneis, rwaurhpeitcitohwninointdueralnetcaotrcpiceearnlattpeeorwws ealotreccraamnteahdnaavingeecPmaosercntatldasinnysgdt,eimGmpWsa. cBItesacntahdursoeuoghf out
rcaeorosmpuomnndusnlietinhifcefienar,ftawrwiosaotsnhrrtsirulcducch.chtFtahuuunrrarneetshe.sielEsmur;,accpahcolhvmiacasoarmeitfeuvitotanyhncitoeuyssfasfetionhiofecrrnloath,esmdotrerswpul;ivcaowetnnurdeerye,nhta—ehtnsaidinlnthhkrcaeluacvsadpberiooneangufssatdeecitrsirlhaivotesiiuectetsee—rs; a rFeirgsiotnL.iAghsttePcohrntolalongdy,aadnvdannceosn, einfirnasStrouuctuhrePoisrbtleacnodm. iBnog tehven more
can savevulivlneseraanbdilpitryotoefctthcoemsemcuonmitiepso. nents to climate hazards. intdearctaoncneenctteedrstharroeuignhdthoewinnttroowduncPtioonrtolafn“sdmnaerta”rteCcohnnogrloegsiess. For
oAtrfasinnpsfeprcaoisfrwFttihctriaiugelptlcuiroltmoiurnkegroeernlra3yeesm.te2rwsrme7ivogaaiirccntnkeihicdsfaiietcltclhhxoaaaaewnttmietsrespifunmalteasrhbmpeiaslfaeetuFcraleTtsgssnFrte,doifwcrruvoauhlictsmiccuceeherrecslisisalfdimnesseeudvbaepetdsepleoyfoaospcrntmrthdeeeaemdswnnebtgldel.yeAetsh.aveesirteciarreonsngeg eeisxlecSraceotmtlrinraepicfneilecetta,r,otunminos.eniaWnkofooifhnfreitmglnreaeafnlttrohisgopoyenodsdramitnnaaadtgtraiotcocongremrisinndmectsraeuemrnlaeseiscveagaensteilstonhrtneihesraiendatfelirelspyansseehutnrraedugvsyecetnliuencdrfseerisva,osewoftrrfhtsuriaelacentutshrpeeor t
produceDteopienntedrimnegdoiantethmearlokectast; iaorne,lidabalteawcaetnetresrupapnldy itsracrnitsicmalisfosiron neutwndoerkrsgroonutnhde ppoowweerrgfreide.Wdshailnedthbeaseckaudpvagnecensecraantosrusp,port efficiency
irrigationin; fernaesrtgryuncetutwreorinksstsaulplepdorttoadgariycumltuaryabl peroafcfeescsitnegdfabcyilitsieesa.These anpdorteelinabtiialitlyimacproascstssyustnedmesr, gthreouinntedrdceopuelnddoenccceuroffrinofmrastructure
aadndvaontchelHeefroovioenwldfrerasvisseetecrruu,arcbnitteuyd.cresatusoysrsetmetmhsesuirargrseeefrsuveniedcnaemblievenettwsaleatreoentshnteoillwarbeaillinatytdiov2fe0Fly5T0F.to utongddaraevomorusidacnogdaren,edistmotphprreeoapccaartdristewiccfaaoolyruismdldopisrorruerlaptsantuniodlctnesfsur,ooibnf mcsulisudihndegeinnaagcvestyhyisopstssereuemecdsisupp.eilAtatanbotnoicionvlingme aapteprcohaacnhge.
Inforarshtriugchtuwreinids aelsvoenutnsiqdueeplyernedlaitnegd otoncwlimhaatteincfhraansgteruincttuhartethe
INFRsAhoSrtT, tRheUseCsyTstUemRsEareISbeUtteNr aIbQleUtoEinLcYrementally cEsiongiismennrsiipgnftiyrac,pucbacltuanteicitlddoleyinn.b,Wcgymsotin(areeteimsrnlpiebtpeseucesnit,raaearllnyattucdoinerioedt,huacoesnhtrrdpaisarnaolo)gtp,beeaellnselri.damtettiroosaefnnrsscvploiiocmfreiatsnattfceirooacnushtilnardufnrbcagteseutrriutescetulfr.e
AFFEadCaTptE. InDfraBstYrucCtuLreIMwitAhTsigEniCficHanAtlyNlonGgEer service
and operations are key sources of greenhouse gas emissions. Supporting
lives, such as copper or fiber optic cabling or buildings,
oyIneffarinarssfr.tarSusocwtcmrltiiuumlelcrnteaouetfrseeeythsdhhteeaainmvzmesasotrlaoadstlrnsleaigmptbilripoufoeoinltjtreimattcaonentdesltadtasmhtnf.adaoOtirnusnpsttceehaefnneucaloeonsvnnycessderttre2oupm0fcla,stte5nhidn0se,,ttmechhveeaaennntwytcou1toy0rrlpny0d.eshsidaveer unsustainable infrastructure may give rise to a lock-in effect, whereby

segments that have lasted more than a century (e.g., railways in India, the
subway system in the New York metropolitan area).

Figure 1. SSeerrvivcieceLifLeiofef DoifffeICreTntInInffrraassttrruuctcutruerTeypaensdinCthliemFaatcee CofhLaonngge-teIrmmpCalcimtsate Change1

Figure 3.27. Service life of information and communications technology infrastructure with respect to climate change impacts. Source:
1 AdaptedUfSroAmID: A, EAAd,d2r0e1s0s. AindgapCtilnigmtaheteICCThSaencgtoer Itmo tphaecImtspoacntsInoffrCalismtrautecCtuhraeng, e(:2F0in1a3l )R.9e2port. http://archive.defra.gov.uk/environment/climate/documents/infrastructure-aea-full.pdf

2 OVERVIEW ADDRESSING CLIMATE CHANGE IMPACTS ON INFRASTRUCTURE: PREPARING FOR CHANGE
ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 67

INFRASTRUCTURAL RISK

Climate Change Impacts on ICT Infrastructure and Services

Climate Change Transmissions Infrastructure Wireless Signals Buildings and Equipment
Impact
• Increased heat-related health • Decreased range of wireless • Overheating of data centers,
Temperature Change and safety risks for maintenance signal transmission, resulting in exchanges, base stations, etc.
workers the location/density of wireless
Precipitation Change masts becoming sub-optimal • Increased air-conditioning
requirements and costs
Sea Level Rise and • Increased flooding of low-lying/ • Reduced quality and strength of
Increased Storm Surge underground infrastructure and wireless service due to increased • Decreased heating requirements
Changes in Extreme access points, particularly in rainfall and costs
Storms and Wind coastal areas and floodplains
• Changes in requirements to
• Exposed cables/trunk routes maintain internal environments
due to erosion or damage of of system devices due to changes
transportation infrastructure in humidity

• Increased flooding and salt water • Changes in reference datum for • Closure or reduced access to
corrosion of infrastructure in telecommunication and satellite low-lying coastal buildings due
low-lying/coastal areas transmission calculations to permanent or temporary
flooding
• Fallen cell towers or telephone Minimal Impact
poles from high winds or fallen Minimal Impact
trees

• Increased damage to above-
ground infrastructure

Table 3.15. Potential climate change impacts on information and communications technology infrastructure and services. Table adapted from
USAID, Addressing Climate Change Impacts on Infrastructure, (2013).93

Any impacts to ICT infrastructure tend to be amplified 3.5 Impacts to Sites of
due to interdependencies between infrastructure
systems. ICT networks rely heavily on the power grid, Contaminated Soil and
and when there are service interruptions, back-up power
is usually provided by petroleum generators. In order Hazardous Waste Storage
to have fuel for the generators, the transportation
sector must be functioning. Similarly, infrastructure Historically, the coastal areas of Portland and South
systems are usually collocated, meaning fiber and Portland served as a home for shipping, fishing,
telecommunications lines are usually clustered alongside commerce, travel and industrial uses. Portland’s industrial
transportation infrastructure. Therefore, a bridge failure revolution from the mid- to late-nineteenth century
may disrupt transportation as well as ICT networks. The led to a boom in industries that produced unnatural
collocated telecommunications infrastructure on Pan Am compounds and introduced them to the environment
rail bridges is one prime example.85 without restriction—in particular, tanneries, paint
factories, shipyards, metal foundries, railroad yards,
and a coal-gas plant were the burgeoning Portland-area
industrial sites that had the largest environmental impact
in that time.86

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 68

Home, Sweet HDA: A Neighborhood HistoryINFRASTRUCTURAL RISK

When environmental historian which you live, work, or go to school. continued into the 1900s. Some
Edward Hawes began the detective Then see the list below to learn which continue to this day.

Research commissioned by the CwCaaossrkccotooBdaBiysacmoyivgeEhrtswhtahuevaerercpyoomlleutfarontms ,inhe induHstIrinisedstuoswtrreieriescapDrreesegervnoteuipnleoydepabmrys cpeeannsttut.ryA, reas in 1800s Portla—ncodntinauend odn pg.5
Partnership found that historic ddeisvcoevleorepdmtweonptatitenrntshoen the land that but many activities begun in theS1o8u00tsh Portland
Portland and South Portland areoavserclaOlponpseeedw.laysrweaftleerschetdesd, the
layout of watersheds, as these intdopuosgtrarpiehiscawl neerigehboofrhtoeonds that
reliant on water for processes, pfcournewneekesl ,rwthtaertenarnsimnstaoplltoirnirvyetsr,tsr,aeanemvdes,ntthuaenlly
waste removal (Figure 3.28). Altehmoputyginhg ihntoeathveyBainy.dustry East Deering/Bay Shore
is no longer the backbone of thesuPrroourTnthdlisainsngydsCteaamsncoodf BwSaayoteurcsohtiehndcisdes with
Portland economies, the petroleaumsecotnadnpkasttetrhn.aHtiswtoreicrdeevelopment Capisic Watershed North Side/East Deering

first established in South Portlanebdsesceiannutisatelhleyeamrl1iyr9rion2rds0utshsterihewsaawvteeerrsehed, South Side/Munjoy Hill
continued to make South Portlandedpeandreengt oion nneaalrbhyusbources of water.
for petroleum transportation. StEtrhvieecynthwaehdnelnvittislreeowenfefermsctweoennreltaiannldstaulsleed, Stroudwater in Portland Grand Trunk
regulations now prevent pollutiopnattferronsm, betchauesetathneske fhaumrman-screated
from entering the bay, and yet thowenaethesri—sshteiodnsrsotiecmndeaecndadstoespm, rtihmeeiscsettrhneeatmn-astural West Side/Deering
day uses of the area have led to athehmisgehlveesrwceorentackeennutnrdaetrigoronund South Side/Industrial

Railroad Triangle Central/Commercial Street

Spring Point

West Commercial Street

of contaminated sites and hazardwoithutshHeamwseeawstemer.arpiapledstthoerseagdiestinct Mall Commercial/Industrial Rolling Mills/Ligonia Ferry Village
facilities in these areas (Table 3.1n6ei)g.hborhoods and named them Knightville/Mill Cove

Historic Development Areas, or HDAs. Turner’s island/Pleasantdale
Listed here are the major polluting

Climate hazards pose a significanintdtuhstrrieesathtaot Hfatwraesnidsepnotifiretdiningeach

these materials. Shoreline retreaCHtDodnAusuienlt tPthooertmlasanepdatoolrelSovoceauttlherPthioseretHlaDndA.s in Main Street/Industrial Park Historic Development Areas in
could submerge hazardous material sites currently in the Portland and South Portland

floodplain, expose them to wave action, and incorporate 4 The Dirty History of Portland Harbor
new sites into floodplain areas. More frequent extreme Figure 3.28. Historic development areas in Portland and South
weather events could likewise expose these sites to Portland that correspond with higher levels of contaminants and
wind and wave action, and higher, salt-containing water hazard storage facilities based on their historic and present uses.
tables, which can transport soil-bound pollutants and Figure source: Hawes, E. (2014).94

compromise subsurface containment systems.

Historic Uses Associated With Development Areas in Figure 3.28

Development Area Historic Use

Railroad Triangle Railroad yards with machine shops, slaughterhouses, soap factory, brickyard.
West Back Cove/Deering
Tanneries, varnish and paint factory, foundry, stoneware factory, brickyard.
North Back Cove/East Deering
Pewter and Britannia metal shops, tanneries, book bindery, can factory, galvanizing and plating shop,
South Back Cove/Munjoy Hill possible brickyard.

South Back Cove/lndustrial Tannery, dump, fill at East Promenade.

Grand Trunk Area Considerable filling of the cove, railroad repair yard, Portland Stove Works, machine shops and
metalworking facilities.
Central Commercial Street
West Commercial Street Smelter, cemetery, shipyard, rail yard with machine shop, metal shops, metalworking facilities, major
Spring Point foundry, lead paint factory.
Ferry Village
Knightville/Mill Cove Paint factory, canneries, machine shops and small foundries, galvanizing operations, boat landings.
Turner’s Island/Pleasantdale
Match factory, sugar refinery, railroad yards, gas works, hat factory, petroleum storage/distribution.
Rolling Mills/Ligonia
Military bases.

Shipyard, metalworking facilities.

Dry dock, brewery, and shipyards.

Heavy landfilling, cemetery, rail yard and repair facility.

Substantial landfilling, cemeteries, large iron rolling and fabrication facility, acid chemicals plant,
kerosene refinery, paint and varnish factory.

Table 3.16. Historic uses associated with development areas in Figure 3.28. Table adapted from Hawes, E. (1994).95

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 69

INFRASTRUCTURAL RISK

CURRENT SITES OF CONTAMINATED SOIL AND and South Portland that might be of particular concern
when considered with climate hazards either for the
HAZARDOUS WASTE STORAGE type of contamination, their location, or both. Table 3.17
indicates the different types of sites that are included
Today, the Maine Department of Environmental within the EGAD data and how those sites are defined by
Protection (DEP) tracks data associated with water DEP.
quality and potential and actual sources of contamination
to groundwater in Maine. The data is referred to as The site types in Table 3.17 relevant to Portland and
the Environmental and Geographic Analysis Database South Portland can be grouped into two categories:
(EGAD).87 This database also includes biological and
surface water sampling sites. DEP and staff from the 1. Sites of confirmed or suspected soil contamination,
Bureau of Remediation and Waste Management and the and
Bureau of Water Quality use this information to assess
trends in regional surface and groundwater quality and 2. Hazardous material storage areas.
quantity. The EGAD data was used for this vulnerability
assessment to identify hazardous waste sites in Portland

Site Type EGAD Site Type Definitions

Large Bulk Fuel Storage/ Definition
Distribution Facility
A group of large above-ground storage tanks (ASTs) usually used to store petroleum products, (i.e.,
Leaking Above-ground marine terminals, petroleum distribution facilities), with a total facility volume greater than 1,320
Storage Tank gallons.

Leaking Underground (LAST). A container, 90% or more of which is above the ground, which is used to hold oil and other
Storage Tank petroleum derived products. It is considered to be leaking if there is some evidence that it has
released some of its contents to the environment.
RCRA Large Quantity
Generator (LUST). A container, 10% or more of which is beneath the surface of the ground, which is used to hold
oil and other petroleum derived products. It is considered to be leaking if there is some evidence that
RCRA Medium Quantity it has released some of its contents to the environment.
Generator
A Resource Conservation and Recovery Act (RCRA) Fully Regulated Generator that generates more
RCRA Small Quantity than 1,000 kilograms (2,205 lbs) of hazardous waste per month. Hazardous waste cannot be stored
Generator more than 90 days from date of generation.

Sand/Salt Storage A Resource Conservation and Recovery Act (RCRA) generator that generates between 100 and 1,000
Sanitary & Industrial kilograms (220-2,205 lbs) of hazardous waste per month, either on average per month or exceeding
100 kg in any one month.
WWTF
A Resource Conservation and Recovery Act (RCRA) generator that generates less than 100 kilograms
Surface Spill (220 lbs) of hazardous waste per month AND accumulates no more than 55 gallons (1 drum; ~208 kg)
of hazardous waste per month.
Uncontrolled Site,
All Other An area at which salt, or sand-and-salt, are stored in preparation for road and highway deicing.

A wastewater treatment facility (WWTF) used for treating sanitary or industrial wastewater. This may
include spray irrigation sites, aerated lagoons, stabilization ponds, polishing ponds, sand filters, and
other similar structures used for that purpose.

A site where oil has been released onto the ground, not caused by a leak from a storage tank. Common
examples include heating oil and gasoline tank overfills, tanker truck accidents, and releases from
gasoline tanks mounted on vehicles.

An uncontrolled hazardous substance site. A location at which hazardous substances came to be
located, where the site poses a threat or hazard to any person or the natural environment and requires
action to abate.

Table 3.17. Environmental and Geographic Analysis Database (EGAD) site type definitions. Table adapted from Maine Department of
Environmental Protection (2019).96

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 70

Each of these site types is vulnerable in different ways INFRASTRUCTURAL RISK
due to climate hazards such as increased precipitation,
extreme weather, and sea level rise. While the specific site subject to various restrictions; the large bulk fuel
climate vulnerabilities of these sites will be touched storage facilities; and the one wastewater treatment
on throughout the discussion of their locations, the facility identified as being vulnerable to the sea level rise
vulnerabilities are more thoroughly summarized in scenarios used for this discussion. It is important to keep
Table 3.18. The sites of confirmed or suspected soil in mind throughout this discussion that the EGAD data
contamination in Portland and South Portland include identifies single points, such as the location of a tank
the sites of former LASTs, LUSTs, surface spills, and farm, that may contain multiple hazards, such as multiple
salt storage, as well as uncontrolled sites. The sites of tanks.
hazardous material storage include the RCRA waste
generators, as they are permitted to store material on The EGAD data was analyzed along with the Maine
Geological Survey (MGS) Sea Level Rise/Storm Surge
data (2018). As mentioned in the introduction to the

Impacts of Climate Hazards on Vulnerable Hazardous Material Sites

Climate Hazard Vulnerable Site Type Potential Effect

Changes in water Contaminated Soil Mobilization of contaminants (e.g., from vadose zone to groundwater) →
tables and increased Higher contaminant concentration/export, overpowering significant
groundwater salinity Hazardous Material degradation rate in groundwater zone could remove natural protective
Storage barriers
Sea level rise
Contaminated Soil Altered salinity →
Extreme weather Altered degradation rates (physical, microbial)
Hazardous Material
Storage Higher groundwater levels →
Structural damage to subsurface containments due to increased
Contaminated Soil hydrostatic pressures

Hazardous Material Altered salinity →
Storage Damage to clay containing layers

Tidal erosion →
Damage to site integrity, mobilization of soils

Site inundation →
Increased mobilization of contaminants, increased bioavailability of
contaminants

Tidal erosion →
Damage to containment structure integrity due to saltwater corrosion or
hydrostatic loads of inundation

Site inundation →
Containment structure overflow, floating or spilling of improperly secured
containers

Wind/wave action; surface water flow velocity →
Scouring, mobilization of soils

Flooding →
Contaminant export

Wind/wave action; surface water flow velocity →
Structural damage to containment structures by wind and hydrodynamic
loads as well as debris

Flooding →
Structural damage to containment structures by hydrostatic loads

Table 3.18. Impacts of climate hazards on vulnerable hazardous material sites. Table adapted from Maco, et al. (2018);97 with information from
Flynn, T.J. et al. (n.d.).98

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 71

Infrastructure Section of this report, the MGS sea INFRASTRUCTURAL RISK
level rise scenarios selected correspond with the Low-
Intermediate, Intermediate, Intermediate-High, and High lower two thresholds for 2100 (1.6 and 3.9-foot rise
scenarios for 2100. Under the Intermediate scenario, we above HAT). An overview of the sites identified within the
would expect to see 1.48 feet of relative sea level rise by EGAD dataset that may be specifically impacted by sea
2050 for the Greater Portland area—or up to 3.38 feet level rise is presented in Figure 3.29.
under the Extreme scenario. For the sake of visualization,
these 2050 thresholds roughly correspond with the Vulnerabilities identified within the 1.6-ft scenario
include two RCRA Small Quantity Generators (SQGs)
in the Central Waterfront District of Portland, a site of

Vulnerable Hazardous Waste Sites in Portland and South Portland

Figure 3.29. Vulnerable hazardous waste sites in Portland and South Portland based on four scenarios of sea level rise (1.6, 3.9, 6.1, and 8.8
feet on top of the highest astronomical tide). Data sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological
Survey Sea Level Rise/Storm Surge Scenarios (2018).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 72

INFRASTRUCTURAL RISK

petroleum waste sludge buried on Turner Island and but SQGs are not required to have a written contingency
potentially contained by a suspected clay layer below plan.89 In a worst-case scenario, a severe flood event
(considered Large Bulk Fuel Storage in the EGAD data), could hit at a time when vulnerable SQGs are storing the
several aboveground storage tanks (ASTs) also on maximum amount of waste permitted.
Turner Island, and an AST in the Knightville area of South
Portland (Figure 3.30 and Table 3.19). All 1.6-ft Sea Level Rise Vulnerabilities by Type

According to Maine DEP, SQGs may accumulate Vulnerability Type Number of Sites
hazardous waste on site for 180 days, though this
quantity may never exceed 440 pounds or 55 gallons.88 Large Bulk Fuel Storage 3
The EPA regulates that the waste must be managed Small Quantity Generators 2
in tanks or containers, and an emergency coordinator
must always be available to respond in an emergency, Table 3.19. Vulnerable hazardous waste sites in Portland and
South Portland based on inundation from 1.6 feet of sea level rise
on top of the highest astronomical tide (HAT).

Selected 1.6-ft Sea Level Rise Vulnerabilities

Figure 3.30. Vulnerable hazardous waste sites in Portland and South Portland based on 1.6 feet of sea level rise on top of the highest
astronomical tide. Data sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological Survey Sea Level Rise/Storm
Surge Scenarios (2018).

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INFRASTRUCTURAL RISK

In the case of a 1.6-ft tide increase, the three sites of The vulnerabilities within the 3.9-ft scenario include
above-ground storage—the two SQGs and the AST— four sites with contaminated soils, including the site
could be subject to wave action and corrosion by of a former salt pile, several large ASTs, and a number
saltwater. Should there be a violent storm and flooding, of Small, Medium and Large Quantity Generators. The
these tanks would be the first to be subjected to damage
or dislodgement by forceful wave action, or hydrostatic All 3.9-ft Sea Level Rise Vulnerabilities by Type
pressures should they be submerged.
Vulnerability Type Number of Sites
As sea levels rise, so do groundwater levels, and the
buried petroleum waste sludge may become vulnerable Soil Contamination 5
to migration.90 Increased saltwater content in the Small Quantity Generator 4
groundwater could potentially allow water to permeate Medium Quantity Generator 5
the clay layer suspected to contain the waste, which is Large Quantity Generator 1
normally impervious to freshwater, subjecting the waste
to solution and migration.91 Table 3.20. Vulnerable hazardous waste sites in Portland and
South Portland based on inundation from 3.9 feet of sea level rise
on top of the highest astronomical tide (HAT).

Selected 3.9-ft Sea Level Rise Vulnerabilities

Figure 3.31. Selected vulnerable hazardous waste sites in Portland and South Portland based on 3.9 feet of sea level rise on top of the highest
astronomical tide. Data sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological Survey Sea Level Rise/Storm
Surge Scenarios (2018).

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majority of these vulnerabilities are concentrated in the INFRASTRUCTURAL RISK
low area of Portland’s Bayside area along Back Cove
(Figure 3.31 and Table 3.20). storage tanks near Bug Light, depicted in Figure 3.32, fall
within low-lying, vulnerable areas with 3.9 feet of sea level
According to Maine DEP, MSQs may not accumulate rise. The berms will likely protect the tanks from wave
more than 1,320 pounds of hazardous waste on site action and corrosion on a regular basis, but these areas
and may store this amount for up to 180 days. LQGs could be inundated if back-up pumps were to fail.
do not have a limit on the amount of hazardous waste
accumulated onsite, but they may only accumulate The particularly high density of ASTs in the Portland
material for 90 days. LQGs must have a written and South Portland area, and their vulnerability to sea
contingency plan and an emergency coordinator available level rise, is particularly evident when looking at the
at all times. The vulnerable sites shown in Figure 3.31 number of these tanks within a quarter mile of the South
are largely MQGs, in addition to the two SQLs, two Portland’s Fore River coastline to the east of the Veterans
contaminated soil sites, and a former salt pile that are Memorial Bridge—there are approximately 100 ASTs in
brought into the 3.9-ft HAT rise. These sites are subject this zone, and by the time of the 6.1-ft HAT rise, 37 will be
to the same considerations discussed in the previous in low-lying areas that could be vulnerable to the highest
section, including damage to storage mechanisms and astronomical tide. As previously stated, it is important
transport of pollutants. In addition, 7 of the 13 large to keep in mind that each point represents a site in the
EGAD data that Maine DEP tracks, but each site may
consist of multiple storage tanks. In Figure 3.33, the

Storage Tanks near Bug Light with Exposure to Sea Level Rise

Figure 3.32. Seven of thirteen storage tanks near Bug Light show vulnerability under the 3.9-foot sea level rise scenario. Tanks are protected
by berms and not directly exposed to tides, but are in low-lying areas that may be vulnerable to flooding if protection systems were to fail. Data
sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).

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INFRASTRUCTURAL RISK

large number of ASTs within the quarter mile buffer are At the sites with contaminated soils, pollutants could
evident, despite there being only a few points from the be transported through the ground by the higher
EGAD data, as compiled in Table 3.21. In addition to the groundwater levels that would result from higher sea
ASTs, the vulnerabilities within the 6.1-ft scenario include levels, and damage due to wave action or flooding could
eight contaminated soil sites, including a former salt pile, completely remove and transport contaminated soil
and several SQGs and MQGs. layers. With respect to the many above-ground storage

The South Portland WWTF located at 111 Waterman All 6.1-ft Sea Level Rise Vulnerabilities by Type
Drive could experience structural damage or failure due
to loads from wave action and water inundation, impact Vulnerability Type Number of Sites
from moving debris in a violent flood, or corrosion from
salt exposure. The East End and Peaks Island Wastewater Soil Contamination 8
Treatment Facilities, while included in the EGAD data, are Large Bulk Fuel Storage 3
at elevations such that they are not vulnerable to the sea Small Quantity Generator 8
level rise scenarios modeled. However, they are still at Medium Quantity Generator 2
risk of climate hazards concurrent to sea level rise, such Wastewater Treatment Facility 1
as more frequent and more powerful storms. As they
are situated on the shoreline, it is certainly possible that Table 3.21. Vulnerable hazardous waste sites in Portland and South
during a violent coastal storm, these other treatment Portland based on inundation from 6.1 feet of sea level rise on top
plants could be at risk of similar threats. of the highest astronomical tide (HAT).

Selected 6.1-ft Sea Level Rise Vulnerabilities

Figure 3.33. Selected vulnerable hazardous waste sites in Portland and South Portland based on 6.1 feet of sea level rise on top of the highest
astronomical tide. Data sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological Survey Sea Level Rise/Storm
Surge Scenarios (2018).

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INFRASTRUCTURAL RISK

tanks identified within the 8.8-foot rise, tanks could be All 8.8-ft Sea Level Rise Vulnerabilities by Type
structurally damaged by debris, wave and hydrostatic
pressures, and corrosion, or could even be dislodged by Vulnerability Type Number of Sites
wave action and spill.
Soil Contamination 5
The vulnerabilities within the 8.8-ft scenario include Large AST 2
38 additional storage tanks along the South Portland 4
coastline discussed previously, as well as several RCRA Small Quantity Generator 3
generators and sites of contaminated soils, depicted in Medium Quantity Generator
Figure 3.34 and listed in Table 3.22. The 8.8-ft scenario
vulnerabilities in Portland are largely the contaminated Table 3.22. Vulnerable hazardous waste sites in Portland and
sites and waste generators, while the vulnerabilities in South Portland based on inundation from 8.8 feet of sea level rise
South Portland are largely storage tanks. on top of the highest astronomical tide (HAT).

Selected 8.8-ft Sea Level Rise Vulnerabilities

Figure 3.34. Selected vulnerable hazardous waste sites in Portland and South Portland based on 8.8 feet of sea level rise on top of the highest
astronomical tide. Data sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological Survey Sea Level Rise/Storm
Surge Scenarios (2018).

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PRIORITY AREAS INFRASTRUCTURAL RISK
Based on the assessment above, there appear to be two
most critical areas for all the projected scenarios: foot rise in HAT along the Fore River, but even the sites
that are not brought into the tidal zone are subject to
• Portland’s Bayside area along Back Cove, and the impacts of extreme weather. For the Intermediate
• The low-lying areas of South Portland along the Fore scenario, more ASTs along the Fore River shoreline are
brought into the tidal zone, as well as some MQGs and an
River with a high concentration of large bulk storage LQG, and these are the most critical areas of concern.
tanks.
There are many contaminated soil sites in the Portland
The most critical vulnerable sites are the hazardous and South Portland area monitored by Maine DEP and
material storage areas; in particular, the Large ASTs included in the EGAD data, as well as the many more that
and Medium and Large Quantity Generators. For this likely exist as a result of the areas’ industrial past. Most
reason, the Fore River Shoreline appears to be of highest of the soils in the area are held in place by development,
concern. All the ASTs in this area, along with the 8.8-ft and the transport of their contaminants would not be
scenario for reference, are highlighted in Figure 3.35. as acute a threat as the potential transport of the huge
volumes of hazardous materials stored in containment
For the Low-Intermediate sea level rise scenario, relevant systems along the Fore River shoreline in South Portland
to 2050, the most critical vulnerability appears to be the and, to a lesser extent, those materials potentially stored
ASTs that enter into the inundation area for the 1.6- by RCRA Generators in the Bayside Area of Portland.

ASTs Along the Fore River Shoreline

Figure 3.35. Above ground storage tanks (ASTs) along the Fore River shoreline overlaid with projected inundation from 8.8 feet of sea level rise
on top of the astronomical high tide. A portion of the ASTs are far enough inland and/or protected by berms so as not to be directly affected
by tidal inundation. Further hydrological study is necessary, however, to assess the flood risk of these tanks, particularly in low-lying areas. Data
sources: Maine Department of Environmental Protection, EGAD (2019); Maine Geological Survey Sea Level Rise/Storm Surge Scenarios (2018).

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INFRASTRUCTURAL RISK

SECTION THREE ENDNOTES 80 Portland Water District (2017). Sebago Lake Watershed Map.
As cited in Sebago Clean Waters. Retrieved from https://www.
62 U.S. Department of Homeland Security. (2016). Casco Bay sebagocleanwaters.org/watershed-map
Region Climate Change Resiliency Assessment. Regional
Resiliency Assessment Program. 81 Woodard & Curran. (2013). CMOM Assessment and
Corrective Action Plan Report. Retrieved from https://www.
63 Comes, T., & Van de Walle, B. (2014). Measuring Disaster portlandmaine.gov/DocumentCenter/View/13789/20131118-
Resilience: The Impact of Hurricane Sandy on Critical CMOM-Report
Infrastructure Systems. Proceedings of the 11th International
ISCRAM Conference. Hiltz, S.R., Pfaff, M.S., Plotnick, L. & Shih, 82 City of South Portland. (2019). Wastewater Plant O&M.
P.C. eds. Pennsylvania, USA. Retrieved from https://www.southportland.org/departments/
water-resource-protection/treatment-systems/pump-station-
64 Local energy systems expert, GridSolar. (2019). Portland, ME. o-m/
65 U.S. Department of Homeland Security. (2016). Casco Bay
83 Chinowsky, P., Helman, J., Sahil, G., Neumann, J., & Martinich,
Region Climate Change Resiliency Assessment. Regional J. (2019). Impacts of climate change on operation of the US
Resiliency Assessment Program. rail network. Transport Policy. 75: 183-191.
66 U.S. Energy Information Administration. (2016). State Energy
Data System, Table C1. Energy Consumption Overview: 84 U.S. Department of Homeland Security. (2016). Casco Bay
Estimates by Energy Source and End-Use Sector. Region Climate Change Resiliency Assessment. Regional
67 U.S. Department of Homeland Security. (2016). Casco Bay Resiliency Assessment Program.
Region Climate Change Resiliency Assessment. Regional
Resiliency Assessment Program. 85 U.S. Department of Homeland Security. (2016). Casco Bay
68 City of Portland. (2017). Portland’s Plan 2030. Portland, ME. Region Climate Change Resiliency Assessment. Regional
69 U.S. Department of Homeland Security. (2016). Casco Bay Resiliency Assessment Program.
Region Climate Change Resiliency Assessment. Regional
Resiliency Assessment Program. 86 Hawes, E. (1994). The Dirty History of Portland Harbor.
70 Union of Concerned Scientists. (2014). The Climate Risks of Casco Bay Estuary Partnership, Muskie School of Public
Natural Gas. Retrieved from https://www.ucsusa.org/sites/ Service, University of Southern Maine. Portland, ME.
default/files/legacy/assets/documents/clean_energy/Climate- Retrieved from https://www.cascobayestuary.org/wp-content/
Risks-of-Natural-Gas-Full-Infographic.pdf uploads/2018/02/2006-Dirty-History-Fact-Sheet-1994-reprint.
71 Portland Water District. (2019.) Annual Water Quality Report. pdf, 1994.
Retrieved from https://www.pwd.org/sites/default/files/annual_
water_report_2019.pdf. 87 Maine Department of Environmental Protection. (2019).
72 City of Portland. (2017). Portland’s Plan 2030. Portland, ME. EGAD (Environmental and Geographic Analysis Database).
73 City of South Portland (2019). Water Resources Protection Retrieved from http://www.maine.gov/dep/maps-data/egad/
Department.
74 City of South Portland. (2019). Wastewater Plant O&M. 88 Maine Department of Environmental Protection. (2018).
Retrieved from https://www.southportland.org/departments/ Handbook for Hazardous Waste Generators. Retrieved
water-resource-protection/treatment-systems/pump-station- from https://www.maine.gov/dep/waste/hazardouswaste/
o-m/ documents/hazardous-waste-handbook-2018.pdf
75 FEMA (n.d.) “Definitions of FEMA Flood Zone Designations.”
FEMA Map Service Center. Retrieved from https://snmapmod. 89 U.S. Environmental Protection Agency (EPA). (2019).
snco.us/fmm/document/fema-flood-zone-definitions.pdf Categories of Hazardous Waste Generators. Retrieved from
76 U.S. Department of Homeland Security. (2016). Casco Bay www.epa.gov/hwgenerators/categories-hazardous-waste-
Region Climate Change Resiliency Assessment. Regional generators.
Resiliency Assessment Program.
77 Burillo, D. (2018). Effects of Climate Change in Electric Power 90 Flynn, T.J., Walesh, S.G., Titus, J.G., & Barth, M.C. (n.d.)
Infrastructures. Retrieved from 10.5772/intechopen.82146 Implications of Sea Level Rise for Hazardous Waste Sites in
78 U.S. Department of Homeland Security. (2016). Casco Bay Coastal Floodplains. Retrieved from http://citeseerx.ist.psu.
Region Climate Change Resiliency Assessment. Regional edu/viewdoc/download?doi=10.1.1.391.7715&rep=rep1&type=pdf
Resiliency Assessment Program.
79 U.S. Department of Homeland Security. (2016). Casco Bay 91 Kebede, A.S. (2009). Assessing Potential Risks of Impacts
Region Climate Change Resiliency Assessment. Regional of Climate Change on Coastal Landfill Sites: A Case Study
Resiliency Assessment Program. of Pennington Landfill Site - Hampshire, United Kingdom.
(Unpublished master’s thesis). University of Southampton,
Southampton, England.

92 USAID. (2013). Addressing Climate Change Impacts on
Infrastructure: Preparing for Climate Change. Washington DC.

93 USAID. (2013). Addressing Climate Change Impacts on
Infrastructure: Preparing for Climate Change. Washington DC.

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94 Hawes, E. (1994). The Dirty History of Portland Harbor.
Casco Bay Estuary Partnership, Muskie School of Public
Service, University of Southern Maine. Portland, ME.
Retrieved from https://www.cascobayestuary.org/wp-content/
uploads/2018/02/2006-Dirty-History-Fact-Sheet-1994-reprint.
pdf, 1994.

95 Hawes, E. (1994). The Dirty History of Portland Harbor.
Casco Bay Estuary Partnership, Muskie School of Public
Service, University of Southern Maine. Portland, ME.
Retrieved from https://www.cascobayestuary.org/wp-content/
uploads/2018/02/2006-Dirty-History-Fact-Sheet-1994-reprint.
pdf, 1994.

96 Maine Department of Environmental Protection. (2019).
EGAD (Environmental and Geographic Analysis Database).
Retrieved from http://www.maine.gov/dep/maps-data/egad/

97 Maco, B. et al. (2018). Resilient remediation: Addressing
extreme weather and climate change, creating community
value. Remediation. Retrieved from https://onlinelibrary.wiley.
com/doi/abs/10.1002/rem.21585

98 Flynn, T.J., Walesh, S.G., Titus, J.G., & Barth, M.C. (n.d.)
Implications of Sea Level Rise for Hazardous Waste Sites in
Coastal Floodplains. Retrieved from http://citeseerx.ist.psu.
edu/viewdoc/download?doi=10.1.1.391.7715&rep=rep1&type=pdf

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ENVIRONMENTAL RISK

4. Environmental
Exposure, Risk, and Vulnerability

Casco Bay Watershed

Portland's and South Portland's
ecosystems are already changing
in response to climate change.

ENVIRONMENTAL CONTEXT Figure 4.1. Map of the Casco Bay Watershed. Figure source: Casco
The Casco Bay Watershed spans nearly 1,000 square Bay Estuary Partnership (2017).
miles in southern Maine. It is rich with forests, soils, and
wetlands that support wildlife, filter air and water, help to resources. Roughly 4 percent of Portland’s area is
buffer extreme temperatures, and enhance our quality made up of parks, land bank properties, and Portland
of life. The water from snowmelt, streams, rivers, and Trail networks;99 likewise, roughly 4 percent of South
rainwater collect and travel through 42 communities Portland’s area includes city-managed parks, fields,
within the watershed, running into Casco Bay and the and open space,100 and roughly 400 acres in South
broader Gulf of Maine. The Gulf of Maine and Casco Portland are conservation land.101 Although few areas
Bay are closely intertwined, exchanging nutrients are undisturbed or contiguous, these spaces provide
and marine life that are collectively impacted by the habitat for small animals and plant life. Portland, in
acidity, temperature, and salinity conditions of these particular, highlights its native, old-growth tree stands—
environments. most notably Deering Oaks and Baxter Woods. These
resources, including the parks, multiuse trails, passive
Portland and South Portland’s connection to water open spaces, and water access points, play a role in
resources serves as a defining feature for both cities. creating healthy and thriving places to live, work, and
Portland and the majority of South Portland sit within play.
the far eastern edge of the Casco Bay Watershed,
where the watershed meets the bay (Figure 4.1). (The
southern edge of South Portland sits within the Saco
River Watershed, which drains into Saco Bay.) The
Fore, Presumpscot, and Stroudwater Rivers, as well as
numerous other freshwater streams that run into the
Fore River, serve as some of the cities’ primary water
conduits. Both the Fore River and Back Cove—Portland’s
large tidal basin—offer important habitat for estuary
ecosystems. Likewise, Casco Bay and the Gulf of Maine
support abundant marine species, many of which
generate key value to the coastal economy.

Despite being urban in nature, Portland and South
Portland also have important land-based environmental

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ENVIRONMENTAL RISK

Climate change has already begun to create strain on increase water flow velocity, create scour, and undermine
ecosystems and has the potential to lead to long-term the resilience of the marshes. As sea levels rise, marshes
impacts to the cities’ critical environmental resources. will continue to lose suitable habitat, particularly at these
While the cities’ water ecosystems provide significant points.
assets to the cities, they in particular show significant
vulnerability. Five specific environmental issues are The process by which tidal marshes gradually shift inland
highlighted in this section: onto formerly dry land or nontidal areas as sea levels
rise is known as marsh migration. Migration is possible
• Marsh Migration where there are not constraints from the developed
• Coastal Erosion environment or steep slopes. In areas where marshes
• Compromised Natural Water Systems are buffered by the built environment, shifting may not
• Shifting Habitats, Pests, and Invasives be possible. Losing these critical marsh ecosystems will
• Species Health Impacts from Ocean and Coastal impact the plant and animal habitats that thrive there
as well as decrease natural flooding buffers, making the
Acidification areas further inland more vulnerable to storm surge.

Understanding how and where the environment is In 2013, the Casco Bay Estuary Partnership (CBEP) looked
vulnerable will help inform the necessary choices at the impacts of sea level rise on wetlands throughout
and strategies for ensuring the cities’ environmental Casco Bay. The study specifically identified four primary
resources remain healthy despite a changing climate. areas in Portland and three in South Portland where
marsh migration is likely to occur due to sea level rise,
4.1 Marsh Migration and where these areas may come into conflict with
existing development:
Climate hazards, and in particular sea level rise, are
known to impact sensitive tidal areas including marshes • Upper Fore River Area (Figure 4.2)
and wetlands. These coastal ecosystems provide • Back Cove Area (Figure 4.3)
tremendous benefit to wildlife, plant species, and the • Commercial Street Area (Figure 4.4)
surrounding built environment by serving as habitat • East Deering Area (Figure 4.5)
and a protective barrier against storm surge and rising • Bug Light and Southern Maine Community College
sea levels by buffering wave action. Marshes also have
the natural ability to filter various types of pollution and Area (Figure 4.6)
slow the impacts of erosion, which can cause property
damage in developed areas. In Maine, marshes are a • Mill Creek and Turner Island Area (Figure 4.7)
unique resource since much of the coastline has a • Forest City Cemetery Area (Figure 4.8)
steep topography. Preserving and protecting marsh
and wetland areas are of interest to many coastal For each site, CBEP assessed the marsh migration driven
communities due to the benefits they provide. by one foot and three feet of sea level rise. Flood extents
are determined by static inundation modeling based on
In mostly urban environments such as Portland and storm tide levels overlaid with LIDAR data. The figures for
South Portland, marshes have already been significantly three feet of sea level rise are included below. To see the
reduced or degraded from development and from analysis at one foot, see the Portland and South Portland
pollution from stormwater runoff.102 Infrastructure, editions of Sea Level Rise and Casco Bay’s Wetlands: A
including roads, bridges, dams, and railroads that cross Look at Potential Impacts (2013).103
tidal wetlands interfere with the way water exchanges
from one side of the infrastructure to the other, and can Upper Fore River Area – A portion of the Upper Fore
River is shown in Figure 4.2. A three-foot rise in sea
level would lead to marsh migration inland in a number
of directions, and would likely result in conflicts with

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ENVIRONMENTAL RISK

existing infrastructure and developed areas. Potential The points where marshes are impeded by infrastructure
instances where marsh migration comes into conflict and development creates heightened risk for losing
with the built environment include: wetland ecosystems. In the upper Fore River this
vulnerability is mitigated slightly by the Fore River
• Stroudwater Village Causeway Sanctuary where the natural area and elevations are
• Low-lying areas of Stroudwater Village including suitable in some spots for inland marsh migration.

portions of outer Congress Street Back Cove Area – Figure 4.3 shows potential marsh
migration in Back Cove, driven by three feet of sea
• Three culverts where the railroad tracks cross the level rise. Baxter Boulevard and the Bayside area are at
elevations where marsh migration would “naturally”
Fore River Sanctuary occur, yet the land use precludes marsh migration. The
brooks near Back Cove Estates and Payson Park allow
• Developed areas associated with Starbird Lane,

Winding Way, Meadowbrook Lane, Frost Street, Cliff
Street, Yellowbird Road

Potential Marsh Migration: Upper Fore River Potential Marsh Migration: Back Cove

Figure 4.2. Potential marsh migration and areas of conflict in Figure 4.3. Potential marsh migration and areas of conflict in
the Upper Fore River (Stroudwater) under 3 feet of sea level rise. Back Cove under 3 feet of sea level rise. Yellow areas represent
Yellow areas represent existing wetlands that will be lost, and pink existing wetlands that will be lost, and pink areas represent areas
areas represent areas where wetlands would naturally migrate, but where wetlands would naturally migrate, but are prevented due
are prevented due to development. Dots specify conflict points to development. Dots specify conflict points between marshes
between marshes and infrastructure. Figure source: Casco Bay and infrastructure. Figure source: Casco Bay Estuary Partnership
Estuary Partnership (Bohlen et al., 2013). (Bohlen et al., 2013).

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ENVIRONMENTAL RISK

for more natural tidal movement, already support marsh few suitable areas for marsh migration at this edge of
ecosystems, and would likely be places for further marsh the waterfront. The primary possible area surrounds the
migration; However, the road crossings and culverts current location of Portland Yacht Services.
create limitations for this movement. The current edge
of Back Cove, including the small freshwater brooks East Deering Area (Martin’s Point) – A thin band of
by Back Cove Estates, are within the City’s Shoreland wetlands currently stretches around Martin’s Point, and
Overlay Zone, which offers some protection from into the cove on the western side of Interstate 295. These
development. wetlands are vulnerable to the effects of sea level rise,
and their area will likely be significantly reduced under a
Commercial Street Area – Only small patches of three-foot scenario (Figure 4.5). The I-295 road crossing
wetland exist around the piers in the Commercial Street that mediates the water exchange between the bay and
Waterfront, some of which will likely be lost with three the cove is suggested to further hinder the health of the
feet of sea level rise (Figure 4.4, yellow areas). There are marshes.

Potential Marsh Migration: Commercial Street Potential Marsh Migration: East Deering

Figure 4.4. Potential marsh migration and areas of conflict in Figure 4.5. Potential marsh migration and areas of conflict in
the Commercial Street area under 3 feet of sea level rise. Yellow the East Deering area under 3 feet of sea level rise. Yellow areas
areas represent existing wetlands that will be lost, and pink areas represent existing wetlands that will be lost, and pink areas
represent areas where wetlands would naturally migrate, but are represent areas where wetlands would naturally migrate, but
prevented due to development. Figure source: Casco Bay Estuary are prevented due to development. Dots specify conflict points
Partnership (Bohlen et al., 2013). between marshes and infrastructure. Figure source: Casco Bay
Estuary Partnership (Bohlen et al., 2013).

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ENVIRONMENTAL RISK

Bug Light and Southern Maine Community Mill Creek and Turner Island Area – The area
College Area – A ring of marshland surrounds the spanning Turner Island and Mill Creek (Knightville)
coast around Bug Light Park, Simonton Cove, and the includes a number of small creeks that run into the Fore
adjacent industrial and marine waterfronts. Figure 4.6 River, creating estuaries with substantial stretches of
illustrates where these marshes will likely be lost with existing wetlands. Under three feet of sea level rise, this
three feet of sea level rise. This area has very little room area is likely to lose marshes at the edges of the coves,
for marsh migration, impeded by industrial, commercial, particularly at the mouths of these creeks (Figure 4.7).
and residential development. Losing some of these Unlike many other areas along Portland and South
marshlands may make this area’s waterfront uses, Portland’s coasts, however, this area does offer some
including Willard Beach, increasingly vulnerable to storm areas for marsh migration—notably within Mill Creek.
surge and erosion. (The map also captures the area across the Fore River
in Portland, adjacent to Portland Yacht Services, which
was a previously mentioned area for potential marsh

Potential Marsh Migration: Bug LIght & SMCC Potential Marsh Migration: Mill Creek & Turner Island

Figure 4.6. Potential marsh migration and areas of conflict in Figure 4.7. Potential marsh migration and areas of conflict in the
the Bug Light and Southern Maine Community College (SMCC) Mill Creek and Turner Island area under 3 feet of sea level rise.
area under 3 feet of sea level rise. Yellow areas represent existing Yellow areas represent existing wetlands that will be lost, and pink
wetlands that will be lost, and pink areas represent areas where areas represent areas where wetlands would naturally migrate, but
wetlands would naturally migrate, but are prevented due to are prevented due to development. Dots specify conflict points
development. Figure source: Casco Bay Estuary Partnership between marshes and infrastructure. Figure source: Casco Bay
(Bohlen et al., 2013). Estuary Partnership (Bohlen et al., 2013).

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 85

migration.) A number of road crossings over both Mill ENVIRONMENTAL RISK
Creek and Anthoine Creek, however, are likely to degrade
the health of marshes in these locations and amplify their of sea level rise will likely result in a net loss of wetlands
vulnerability to sea level rise. in this particular area, despite the resilience of the
Forest City Cemetery Area – The outfall of Barberry Barberry Creek system.
Creek is a significant site for existing wetlands, and the
CBEP studies suggest this site has little vulnerability to 4.2 Coastal Erosion
sea level rise up to three feet (Figure 4.8). The primary
losses for wetlands in the Forest City Cemetery area Portland and South Portland are both susceptible to
are projected to occur along the coast of the cemetery. coastal or shoreline erosion. Coastal erosion is a process
Industrial uses on both the South Portland and Portland where events including severe storms, flooding, storm
side of the Fore River in this area prevent any significant surge, sea level rise and human-related activities wear
space for new marsh migration. Consequently, three feet away beaches and dunes over time. Erosion can occur
due to an acute weather-related event or a long-term
Potential Marsh Migration: Forest City Cemetery change in the coastline as waves or currents remove
sand or rocks from the shoreline. Erosion can result in a
Figure 4.8. Potential marsh migration and areas of conflict in the reduction in the storm buffering capacity of beaches and
Forest City Cemetery area under 3 feet of sea level rise. Yellow dunes, and habitat loss for sensitive coastal ecosystems.
areas represent existing wetlands that will be lost, and pink areas Coastal erosion thus also becomes a threat to adjacent
represent areas where wetlands would naturally migrate, but properties and infrastructure, as changes in the shoreline
are prevented due to development. Dots specify conflict points leave them more vulnerable to other severe storms or
between marshes and infrastructure. Figure source: Casco Bay weather patterns. Shoreline erosion is partially driven
Estuary Partnership (Bohlen et al., 2013). by the elevation of high tides, which will continue to
increase as sea levels rise.

In the recent 2017 Cumberland County Hazard Mitigation
Plan, coastal erosion was included as one of the five
highest priority natural hazards impacting communities in
this region, including Portland and South Portland. In the
two communities, the area of most concern for coastal
erosion is Willard Beach in South Portland (Figure 4.9).
The beach is approximately four acres, located between
Fisherman’s Point and Southern Maine Community
College, and used extensively for recreational activities.
Historically, South Portland has protected the sand dunes
at Willard Beach through a proactive beach management
initiative, which has allowed the city to avoid any beach
nourishment efforts for decades. The size of the dunes
and beach will fluctuate year to year, and different areas
of the beach will grow and erode depending on given
forces. As a whole, Willard Beach has been accretive with
a mean dune change rate of +1.3 ft/yr over the period
from 2007-2019 due to management efforts.104 Dry
beach width (DBW), the distance between the mean high
water line and the dunes or seawall, is a good indicator
of the buffering capacity of the beach to storms. DBW
declined slightly between 2018 and 2019, particularly
in the southern half of the beach.105 Although these

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ENVIRONMENTAL RISK

dimensions tend to fluctuate, attendees at the Resilience 4.3 Compromised Natural
Workshop held in May 2019 voiced concern in continuing
to keep erosion at bay at Willard Beach, specifically Water Systems
highlighting the increasing risk sea level rise and storm
surge would create for beach erosion. Both freshwater and saltwater systems in the Casco Bay
Other areas of Portland and South Portland that are Watershed are increasingly affected by climate change,
also vulnerable to erosion and that could affect critical particularly heavy rainfall and higher temperatures.
infrastructure include the Stroudwater Area of Congress Increased precipitation duration and intensity will
Street (a heavily traveled roadway), Back Cove Pump create more stormwater runoff, which can deliver larger
Station, and the South Portland Wastewater Treatment quantities of pollutants into streams, rivers, estuaries,
Plant. Ecological impacts from coastal erosion can result and the bay. Higher temperatures further degrade water
in habitat loss as the natural coastal wetlands and beach quality, primarily through facilitating algal blooms.
areas deteriorate.
STORMWATER POLLUTION
Willard Beach Erosion Hazard Area Stormwater runoff is often contaminated by nutrients,
sediment, bacteria, or even trash, which accumulates
Figure 4.9. Willard Beach and the surrounding residential areas. as it enters source waters. In Casco Bay, many of the
“D1” (Dune 1) marks the frontal dune closest to the water; “D2” stormwater contaminants are from nonpoint sources
(Dune 2) marks the back dunes that lie inland of the frontal dune. such as pet waste, failing septic systems, fuel spills from
The area marked with red hatch delineates the Erosion Hazard boats, pesticides washing off lawns, or oil leaking from
Area (EHA), which includes “any portion of the coastal sand cars. In particular, the Casco Bay Estuary Partnership has
dune system that can reasonably be expected to become part of identified high levels of polycyclic aromatic hydrocarbons
a coastal wetland in the next 100 years” due a number of forces (PAHs), which are primarily from the combustion of fossil
including long-term erosion or short-term erosion from the 100- fuels.106 PAHs accumulate in sediment, as well as travel up
year storm. Areas vulnerable to storm surge with two feet of sea the food chain through bottom dwellers, to fish, and to
level rise, or otherwise included in the AO zone in FEMA flood mammals including humans.
maps are included in the EHA.126
A greater volume of stormwater amplifies the pollution
entering water bodies particularly when it overwhelms
undersized or aging stormwater controls. Overwhelmed
controls are especially problematic for cities with
combined sewer systems, which carry all collected
sewage and stormwater in the same pipe network and
transport it to the treatment plant where it is treated and
discharged into a water body. When heavy precipitation
or snowmelt increases the amount of stormwater in
the system and it exceeds the capacity of the pipes, all
effluent is dumped directly into the ocean untreated,
causing a combined sewer overflow.

NUTRIENT LOADING AND ALGAL BLOOMS
Water quality data collected by the Friends of Casco
Bay show that nitrogen concentrations are notably high
in parts of Casco Bay.107 Stormwater carrying fertilizers
and pet waste, as well as sewage and air pollutants can
contribute to elevated nitrogen levels. Excessive nutrient

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ENVIRONMENTAL RISK

levels, including high levels of nitrogen, make Casco Bay In adjacent areas where shellfishing is not prohibited, the
increasingly susceptible to harmful algal blooms, or the industry has still experienced closures due to toxic algal
rapid increase in a population of algae. Algal blooms blooms. In winter of 2017, a harvesting ban stretched
decrease water quality, lower dissolved oxygen, and lead from Portland to Harpswell when shellfish showed
to potential plant and wildlife die-offs. elevated domoic acid levels, a biotoxin produced by a
large phytoplankton bloom (Figure 4.10).109 Likewise, as
In recent years, there have been documented algal of July 2019, Maine DMR had issued a red tide closure for
blooms in both Back Cove in Portland and Mill Cove mussels, oysters, clams and snails for an area of Casco
in South Portland. This issue can be exacerbated by Bay including Portland and South Portland.110 These
not only excess nitrogen, but also warmer ocean closures impact shellfish harvesting, fisheries operations,
temperatures and higher levels of carbon dioxide local jobs and the economy. Rising temperatures from
absorbed from the atmosphere, which further increase climate change are expected to make similar toxic algal
the vulnerability of Casco Bay to algal blooms. blooms increasingly hard to contain.

IMPACTS ON AQUATIC ECOSYSTEMS Shellfish Closures in 2017 due to Biotoxin Levels
Pollutants and nutrient loading from stormwater runoff
have a wide range of negative effects on water quality Figure 4.10. Shellfish harvesting closures in 2017 due to elevated
and on freshwater and saltwater ecosystems.108 Some of levels of the biotoxin domoic acid caused by a large phytoplankton
these cascading impacts include: bloom. Domoic acid is known to make people sick, and can induce
brain damage. Figure source: Department of Marine Resources, as
• Coastal acidification; reported in the Portland Press Herald (2017).
• Low or reduced dissolved oxygen levels, resulting in

fish die-offs;

• Toxic algal blooms;
• Closure of areas of Casco Bay to shellfishing;
• Loss of eelgrass beds;
• Damage to aquatic habitats;
• Loss of ecological diversity and changes to

ecosystem function.

The shellfish industry in Casco Bay, and specifically
surrounding Portland and South Portland, has seen
repeated and continuous closures due to related water
quality challenges, all driven by factors that show
potential to worsen with climate change. As mentioned
previously, stormwater runoff, often in areas with
combined sewer systems, can lead to higher bacteria
levels. The Maine Department of Marine Resources has
five shellfish classification categories that reflect water
quality. The area of Casco Bay around Portland and South
Portland is classified as prohibited which means closed
to shellfish harvest at all times when water quality testing
either shows elevated levels of fecal bacteria or when
an areas is near a wastewater treatment plant outfall or
another source of pathogens.

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4.4 Shifting Habitats: New ENVIRONMENTAL RISK

Pests and Invasive Species MARINE ECOSYSTEMS
Invasive Species – Casco Bay’s marine ecosystems are
Portland and South Portland are likely to see substantial vulnerable to the threat of invasive species, which are
changes to ecosystems both on land and in water as species that tend to spread to the point that they can
climate change brings more precipitation and warmer air cause harm to ecosystems. Research completed by Casco
and water temperatures. While climate change impacts Bay Estuary Partnership on invasive species in Casco
on habitats and species are not fully understood, it is Bay found that at two specific locations studied in 2013,
known that habitats will shift or redistribute. Climate between one-fifth and one-third of all identified marine
change will provide opportunities for invasive species species were not native.111 Some of these species112 that
that may never have survived in this area in the past are known marine invasives include:
a chance to thrive, grow, reproduce and survive in
environmental conditions that were not previously • Asian Shore Crab
known to this area. In addition to the introduction and • European Green Crab
expansion of invasive species, a decline in native species • Dead Man’s Fingers
can be expected that may have favored past climate • Lacy Crust Bryozoan
conditions which no longer exist (or that have shifted • Hairy-Clawed Shore Crab
further north). The interactions of climate change with • Chinese Mitten Crab
other related stressors and human activities has the • Common Periwinkle
potential to magnify the impacts and threats to marine • Rapa Whelk
and terrestrial ecosystems.
One example documented by CBEP is associated with
Casco Bay Estuary Partnership has specifically identified a decline in eelgrass beds, which is a native seagrass
impacts and key potential areas of concern associated that provides critical habitat and food for other marine
with shifting habitats, new pests, and invasive species as species. Eelgrass plays a valuable role in maintaining
the following: healthy water quality by managing nutrients in the water
and stabilizing sediment. It can also sequester carbon at
• Warmer ocean water temperatures cause shifts a high rate, which is beneficial when there is excess in the
water. Among other environmental stressors, eelgrass
in species’ geographic ranges and the community stands are declining due to the European green crab, a
structure of Casco Bay’s ecosystem, leading to species whose population has exploded in Casco Bay in
declines in some existing fisheries, resources, and recent years due in part to warming waters.
increases in some invasive species, pathogens, pests,
and disease vectors. Figure 4.11 shows areas of Portland and South where
there has been a change in eelgrass distribution over
• Climate change leads to changes in marine and time.113 While pockets around the islands have seen some
growth in density, the eelgrass area adjacent to the East
coastal food webs, altering species composition, End Beach has seen a loss in density and extent, while
making coastal ecosystems less resilient to other most of the areas at South Portland’s water edge have
stressors like invasive species, elevated nutrients seen either no change or a loss in extent. According to
and habitat destruction, and raising chances of the CBEP, between 2001/2002 and 2013, Casco Bay lost more
ecosystem hitting a tipping point. than half of its eelgrass beds.114

• Sea level rise and altered hydrology in tidal wetlands Shifting Native Habitats – Changes in climate will
shift habitats in Casco Bay, affecting ecosystems, species
(due to multiple climate stressors) shifts species distributions, as well as the marine resource economy.
composition, causes both gains and losses of One such concern is the susceptibility of Maine’s lobster
tidal wetland area, and makes the wetlands more
susceptible to invasion by invasive plants.

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ENVIRONMENTAL RISK

Change in Density and Extend of Eelgrass Beds (1997 – 2010)

Long Isl.

Great
Diamond Isl.

Portland Peaks Isl.

South Portland Cushing Isl.

Figure 4.11. Change in eelgrass distribution (density and extent of beds) in the Portland Harbor between 1997 and 2010. Figure source: Maine
Department of Marine Resources, Historical Eelgrass Coverage Viewer (n.d.).

fishing industry to warming water temperatures. Like 90 percent by 2100 due to warming waters.117 The same
much of southern New England, Maine’s lobster industry study suggests that scallops, shrimp and groundfish—all
could see a decline or a shift in habitat northward as the significant species in Maine—could shift northward to
ocean continues to warm. Figure 4.12 illustrates how the waters in Canada if ocean temperatures continue to
density of lobster catches has already shifted significantly rise. In the meantime, the Gulf of Maine is likely to see
since 1970. Recent research predicts that lobster increases in other species that are more accustomed to
populations are likely to shift 200 miles further north as a warmer waters. In particular, the Gulf is seeing increasing
result of climate change.115 Black Sea Bass populations.

In addition to lobster, increasing ocean temperatures TERRESTRIAL ECOSYSTEMS
are resulting in a shift to the north for a number of Invasive Species – Climate change can both inhibit and
other species in the Gulf of Maine. The timeframe for facilitate growth of invasive plant species. Widespread
species shifting their habitats will depend on the pace impacts and changes are not understood but as with
of climate change and the adaptability of an individual other environmental systems, the range and abundance
species.116 Atlantic Cod populations in the Gulf of Maine, of invasive plants are likely to change. Invasive plants tend
in particular, have been declining since before 1990, and to be better able to tolerate or adjust to new climates
recent research suggests that the remaining habitat for than native species, outcompeting native species for
the species in the North Atlantic could shrink by over nutrients, water, sunlight, or pollinators.

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Changing Density of Lobster Catch (1970 - 2017)

Figure 4.12. Changing density of lobster catches off the coast of Northern New England from 1970 to 2017. Lobster catches have shown
a distinctive shift northward, suggesting that the population will continue to shift northward as oceans continue to warm. Source: The
Washington Post, “Gone in a Generation” (2019).127

Invasive plant species are disrupting ecosystems in other marsh plants that support wetland wildlife. Purple
Maine by developing self-sustaining populations that are loosestrife has been able to respond quicker to warming
dominant or disruptive to native species. The aggressive temperatures, and is blooming several weeks earlier than
growth of invasive plants can affect forest regeneration its native competitors.119
and reduce the value of habitat for other species. After
habitat loss, invasive species are the second most critical Forest Pests – Pests are insects or animals that cause
threat to ecosystem diversity. Invasive plant species in destruction to plant species. Throughout the Northeast,
Maine with wide distribution are listed in Table 4.1.118 pests have caused significant damage to native tree
species, as well as forest ecosystems. Climate change
In particular, longer warm seasons and earlier springs has the potential to amplify this impact, by expanding
have provided an advantage for the growth of purple the range and the intensity of pest infestation. Table 4.2
loosestrife, a plant introduced from Europe that now catalogs pests that have already started impacting the
chokes wetland habitats by overtaking cattails and forest ecosystems in Maine.120

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Widespread Invastive Plant Species in Maine

Norway Maple Garlic Mustard Japanese Barberry
Asiatic Bittersweet Autumn Olive Winged Euonymus
Japanese Knotweed Glossy Buckthorn Dame’s Rocket
Yellow Iris Morrow’s Honeysuckle Tatarian Honeysuckle
Purple Loosestrife Black Locust

Table 4.1. Fourteen of the most widespread invasive plant species in Maine. Source: Maine Department of Agriculture, Conservation, and
Forestry (2017).

Emerald Ash Borer Invasive Pest Species in Maine
Asian Longhorn Beetle
Hemlock Woolly Adelgid Brown Spruce Longhorn Beetle
Elongate Hemlock Scale Winter Moth
European Wood Wasp

Table 4.2. Seven of the most invasive pest species affecting trees and forest ecosystems in Maine. Source: University of Maine, Maine Invasive
Species Network (n.d.).

In particular, Portland and South Portland have seen 4.5 Acidification Impacts
evidence of Hemlock Woolly Adelgid (HWA) outbreaks, a on Species Health
pest that infests hemlock trees throughout the northeast
and up the southern Maine coastline. Nearly all hemlock Broadly defined, ocean acidification is caused by the
trees infested with HWA eventually die, creating broader release of carbon dioxide into the atmosphere from
ecosystem repercussions, such as loss of primary habitat burning fossil fuels (cars, buses, homes, industries) and
for the blue-headed vireo and Blackburnian warbler, and when the carbon dioxide mixes with water, it becomes
the replacement of hemlocks with black oaks, black birch more acidic. The Friends of Casco Bay have documented
and other hardwoods.121 There is a significant risk that a rise in the acidity of Casco Bay over the past 15 years.122
warming temperatures will allow this pest to expand in
distribution, including inland and further up the coastline. Coastal acidification is driven by freshwater runoff from
Likewise, warmer winters are likely to expand the tree streams, rivers, and stormwater that have high levels of
decimation cause by winter moth and emerald ash borer, nutrients, such as nitrogen from pet waste, fertilizer, and
which currently affect areas within Portland and South wastewater, entering coastal waters. The excess nitrogen
Portland and/or in neighboring municipalities. results in algal blooms and when they die, the process of
bacterial decomposition consumes oxygen and releases
Vector-borne Diseases – Rising temperatures can carbon dioxide, creating unnatural acidic conditions for
lengthen breeding seasons and expand the distribution coastal habitats and wildlife. See Section 3: Compromised
of insects carrying vector-borne diseases, such as Lyme Water Systems for further details on algal blooms.
disease and West Nile Virus. For further details on the
risk and health impacts from vector-borne disease see Coastal and ocean acidification can result in the inability
section 5.4 Health. of species that live in Casco Bay to survive and flourish
due to two simultaneous factors: an increase in acidity
and a decrease in carbonate availability.

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Marine species with hard protective shells, including ENVIRONMENTAL RISK
clams, lobsters, mussels, shrimp, oysters, scallops, sea
urchins, and cold water coral, combine calcium and the Friends of Casco Bay indicating that levels of calcium
carbonate found in seawater in order to build calcium carbonate, or shell building material, in Casco Bay are
carbonate shells. Higher levels of carbon dioxide already not sufficient enough for organisms to build
decrease the carbonate ion concentration in the water, and maintain their shells. Under severe conditions, high
making it difficult for marine life to grow healthy shells. acidity can dissolve calcium carbonate shells at a faster
As a result, these species have slower growth, thinner rate than they can be formed.
shells, and their mortality rates rise.123
Additionally, more acidic marine environments
In Maine, 87 percent of the landings value of harvested compromise the health and life stages of many marine
or grown species comes from organisms that make organisms. Many types of fish and invertebrate larvae
calcium carbonate shells, suggesting that acidification are unable to develop properly or lose capacity to avoid
may have significant ramifications for the health of predators under more acidic conditions.125 Stunted
Maine fisheries.124 Figure 4.13 shows recent data from growth or survival at the larval stage will eventually
constrict the growth of adult populations.

Monthly Mean Omega Aragonite Data

Figure 4.13. Monthly mean omega aragonite, the scientific term for the calcium carbonate saturation state, in Casco Bay from January
2016 through March 2019. Other than a few months in 2018, calcium carbonate has not been readily available for shell-building species.
Source: Friends of Casco Bay, Casco Baykeeper (2019).128

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SECTION FOUR ENDNOTES 115 Morley, J.W., Selden, R.L., Latour, R.J., Frolicher, T.L., Seagraves,
R.J., Pinsky, M.L. (2018). Projecting shifts in thermal habitat for
99 City of Portland. (2016). Portland Open Space Vision and 686 species on the North American continental shelf. PLoS ONE.
Implementation Plan. Portland, ME. 13(5).

100 City of South Portland. (n.d.) Parks Department. Retrieved 116 Kleisner, K.M., et al. (2017). Marine species distribution shifts on
from https://www.southportland.org/departments/parks- the U.S. Northeast Continental Shelf under continued ocean
recreation-aquaticspool/parks-department/ warming. Progress in Oceanography. 153: 24-36.

101 South Portland Land Trust (n.d.) Mission. Retrieved from https:// 117 Morley, J.W., Selden, R.L., Latour, R.J., Frolicher, T.L., Seagraves,
www.southportlandlandtrust.org/what-we-do R.J., Pinsky, M.L. (2018). Projecting shifts in thermal habitat for
686 species on the North American continental shelf. PLoS ONE.
102 Bohlen, C., Stelk, M., Craig, M., & Gerber, C. (2013). Sea Level Rise 13(5).
and Casco Bay’s Wetlands: A Look at Potential Impacts ([South]
Port-land Edition). Casco Bay Estuary Partnership, Muskie School 118 Maine Department of Agriculture, Conservation, and Forestry
of Public Service, University of Southern Maine. Portland, ME. (2017). Terrestrial Invasive Plant List. Retrieved from https://www.
maine.gov/dacf/php/horticulture/invasiveplants.shtml
103 Bohlen, C., Stelk, M., Craig, M., & Gerber, C. (2013). Sea Level Rise
and Casco Bay’s Wetlands: A Look at Potential Impacts ([South] 119 Nijhuis, M. (2013). How Climate Change is Helping Invasive
Port-land Edition). Casco Bay Estuary Partnership, Muskie School Species Take Over. Smithsonian Magazine. Retrieved from https://
of Public Service, University of Southern Maine. Portland, ME. www.smithsonianmag.com/science-nature/how-climate-change-
is-helping-invasive-species-take-over-180947630/
104 Slovinsky, P. (2019). State of Maine’s Beaches in 2019. Maine
Geological Survey. Augusta, ME. 120 University of Maine. (n.d.) Maine Invasive Species Network.
Retrieved from https://extension.umaine.edu/invasivespecies/
105 NOTE: The Maine Beach Mapping Program provides updated
shoreline data on changes in beach, dune, and dry beach 121 US Environmental Protection Agency. (2016). What
dimensions. See the following reference for further details: Climate Change Means for Maine. Retrieved from
Maine Geological Survey (2019). Maine Beach Mapping Program https://19january2017snapshot.epa.gov/sites/production/
Shoreline Changes. Retrieved from https://www.maine.gov/dacf/ files/2016-09/documents/climate-change-me.pdf
mgs/hazards/beach_mapping/index.shtml
122 Casco Bay Estuary Partnership. (2015). State of the Bay 2015
106 Casco Bay Estuary Partnership. (2015). State of the Bay 2015 Report. Portland, ME.
Report. Portland, ME.
123 U.S. Environmental Protection Agency. (n.d.). Effects of Ocean
107 Casco Bay Estuary Partnership. (2015). State of the Bay 2015 and Coastal Acidification on Marine Life. Retrieved November
Report. Portland, ME. 2019 from https://www.epa.gov/ocean-acidification/effects-ocean-
and-coastal-acidification-marine-life
108 Bohlen, C., Blair, M., Boundy, V., Freshley, C.,Sands, K. (2019).
Nutrient Pollution in Casco Bay, Maine. Casco Bay Estuary 124 Maine State Legislature; Maine Office of Policy and Legal
Partnership, Muskie School of Public Service, University of Analysis; Bentley, Curtis; and Schneider, D. (2015). Report of
Southern Maine. Portland, ME. the Commission to Study the Effects of Coastal and Ocean
Acidification and its Existing and Potential Effects on Species that
109 McGuire, P. (2017). Late-season toxic algae bloom closes most are Commercially Harvested and Grown Along the Maine Coast.
shellfishing areas in Casco Bay. Portland Press Herald. Retrieved
from https://www.pressherald.com/2017/12/06/toxic-bloom-closes- 125 U.S. Environmental Protection Agency. (n.d.). Effects of Ocean
casco-bay-shellfish-industry/ and Coastal Acidification on Marine Life

110 Breton, R. (2019). Longer 'red tide' outbreak impacting Maine 126 Slovinsky, P.A. & Dickson, S.M. (2011). Coastal Sand Dune Geology:
shellfish industry. News Center Maine. Retrieved from https:// Willard Beach, South Portland, Maine. Maine Geological Survey.
www.newscentermaine.com/article/news/longer-red-tide- Augusta, ME.
outbreak-impacting-maine-shellfish-industry/97-f3421fa7-e4c7-
4ced-a0c3-e63b20cd1130 127 Murphy, Z. et al. (2019). “Gone in a Generation.” Huffington Post.
Retrieved from https://www.washingtonpost.com/graphics/2019/
111 Casco Bay Estuary Partnership. (2015). State of the Bay 2015 national/gone-in-a-generation/?utm_term=.452f1f2ce06d#lobster
Report. Portland, Maine.
128 Friends of Casco Bay. (2019). Casco Bay Matters: Advancing the
112 University of Maine. (n.d.) Maine Invasive Species Network. conversation—and action—on climate change. Casco Baykeeper.
Retrieved from https://extension.umaine.edu/invasivespecies/ South Portland, ME.

113 Maine Department of Marine Resources. (n.d.)
Historical Eelgrass Coverage Viewer. Retrieved from
https://maine.maps.arcgis.com/apps/MapSeries/index.
html?appid=ac2f7b3d29b34268a230a060d6b78b25

114 Casco Bay Estuary Partnership. (2015). State of the Bay 2015
Report. Portland, Maine.

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5. Socioeconomic
Exposure, Risk, and Vulnerability

Climate hazards will likely create both cities’ populations continue to shift towards what
repercussions for our local economy, you typically see in urban areas: younger, more educated,
livelihoods, housing security, food and more racially and ethnically diverse (Table 5.1).
security, and public health.
Both Portland and South Portland have vibrant and
As adjacent coastal cities in Cumberland County, Portland diverse economies. The number of jobs in Portland now
exceeds its population, making up 39 percent of jobs in
and South Portland are closely connected in many Cumberland County, 12 percent of jobs in Maine, and
overall a significant economic driver for the region.129
ways by their populations, economies, institutions, and Portland’s leading sectors by number of jobs include
healthcare and social assistance; finance and insurance;
organizations. The two cities make up the two largest and professional, scientific, and technical services,
followed closely by accommodation and food services.
cities in the Greater Portland Metropolitan Area (Figure Likewise, South Portland’s leading sectors include

5.1)—an area comprising of three counties and nearly

half the state’s population. While South Portland’s

demBoAgCrKaGpRhOicUsNDmAoNreALcYlSoISsely resemble Maine’s as a whole,

DRAFT – REVISION 1

Figure 2 Population density map (2010).

Population Density in the Greater Portland Area

Figure 5.1. Population density in the Greater Portland area (2010). Figure Source: PACTs, GPCOG & Stantec (2017).184

9

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SOCIOECONOMIC RISK

retail; healthcare and social assistance; and finance and and housing affordability; and create challenges in food
insurance, also followed closely by accommodation and access. Likewise, higher temperatures, vector-borne
food services. Despite robust economies, both cities diseases, and poor air quality may further affect our
have seen the proportion of households living below the public health.
poverty rate roughly double since 2000.130
The potential impacts, outlined in the following sections,
Climate hazards not only bring risks to Portland and cross regional, local, household, and individual scales.
South Portland’s built and natural environments, but It is important to note that the burden climate change
are also likely to create repercussions on these social brings on these many facets will not necessarily be felt
and economic aspects—including the local economy, equally. How we can continue to strive towards social
livelihoods, housing security, food security, and public equity in our communities thus becomes an increasing
health. Sea level rise and storm surge may inundate some concern. Our quality of life and ability to grow into even
of the cities’ commercial and industrial areas; affect the more vibrant, prosperous, and equitable cities will require
cost of doing business; influence both property values addressing the potential impacts in the following section.

The Economic Contribution of Casco Bay

Figure 3.3C: aIsncdouBsatryyREegmiopnloInydmusetnrty, EGmroplwoythm,eanntd, GSrpoewctiha,laiznadtiSopne,c2ia0l1iz6ation (2016)

Fothifgeeumsrteaptl5eo.y2om.frrSIeMneeondglaautiuit.ornisTcvnetehre:aayetnnEeoXddmM-teaahpSxxelvipIos,arsypel2tmuals0oetse1etensu7dotn.t,1fahdgseMderoara1a0wtl1iao-ntycihseneae,adtarairinionecpdndsae.tqeserIpxcusneepocacnrtluieitsaesmdclnsiezhteaas.adltAlnQeioagrvsCnearalEeifunolleaWroetgcimt,vhraneepetiaolosoCtnhneya-amrsQqrcteeuhoCnoaoBEtntf.iaWeTt1yhnhirn,etee.daigYAninci-oddaavnuxtsaeises(lstu2lrpfs0ey-lpoe1gie6mtnrcs)e.pitsaaThlpltoiheezeyeracrmtietbaihogeuliainnzbonatbin.tnl1i.eSotpihnsniee,zdwceriicehaisagliictizpoeharsntoisisapopmnonedrecitasaiiaosmvluniazraeleauladttesioourleenrtehlsaisdentitvahtemhanetoou1 nt
indicates a smaller relative share of the industry in the region. Figure source: Maine Center for Business and Economic Research and rbouvier

consulting (P20o1p7)u.18l5ation growth and change

Population dynamics underlie all economic change. A region’s ability to grow or decline is
ONE CLIMATEdiFrUecTtUlyREtied|to CthLeIMgArToEwCtHhAoNrGdEeVcUliLnNeEiRnApBIoLpITuYlaAtSioSnES. SLMikEeNwTise,|undPeGr.s9ta6nding interregional population

movements, including where people live and where people work, is important to understanding how

Population Characteristics SOCIOECONOMIC RISK

Characteristic Portland South Portland Maine
Population 66,417 25,606 1,338,404
Population Density (people per square mile) 3,107 2,086
Median Age 36 40.8 43
Percent People Over Age 65 13.7% 15.4% 44.6
Percent People Under Age 18 16.5% 18.3% 20.6%
Percent People of Color 18.9% 7.5% 18.7%
Percent Foreign-Born 13.4% 5.7% 6.9%
Percent with Bachelor’s Degree or Higher 47.6% 42.9% 3.6%
Median Household Income $51,430 $59,515 30.3%
Median Property Value $261,100 $235,700 $53,024
Percent Homeowners 44% 62% $179,900
Poverty Rate 18.3% 12.4% 72%
11.1%

Table 5.1. A selection of population characteristics for Portland, South Portland, and Maine.186

5.1 Local Economy and recreation—accounts for an estimated 4 percent of
gross regional product (GRP) in the Casco Bay watershed
and Livelihoods region, and 8.4 percent of total employment.132

The impact climate change will have on regional or local Harvesting, Processing, and Packaging – Harvesting,
economies is difficult to predict—particularly when tied processing, and packaging of marine species accounts for
to global markets and supply chains. Climate change is 11 percent of the Casco Bay ocean economy GRP ($76
expected to impact the growing capacity of a large range million in 2016), and approximately 1,139 jobs. Although
of natural resources globally, thereby affecting the price this sector makes up a small portion of the full economy
of feedstocks, fodder, and food, and in turn altering the of the Casco Bay region, it holds strong social and
decision-making calculus for a number of industries. cultural importance, including a draw for coastal tourism.
Likewise, disruptions in IT systems, transactions, and
product distribution due to power outages, flooding, or The extensive number of feedback loops and
road closures has significant economic costs. The Maine uncertainties in ecosystem dynamics make it largely
Department of Transportation reports that a trucker infeasible to model the impact of climate change on
incurs $350 of added cost for every hour of unscheduled individual commercial marine species. Nevertheless,
delay, and on average, poor roads in Maine cost scientists from the National Oceanic and Atmospheric
motorists $263 million per year on average (2009 USD).131 Administration (NOAA) have published a recent
assessment of the climate exposure, biological sensitivity,
IMPACT TO ECONOMIC SECTORS and potential change in species distribution for a number
While the impact of climate change on most economic of marine invertebrates and vertebrates.133 Twelve of
sectors in Portland and South Portland remains unknown the species evaluated are of commercial significance
(and is outside the scope of this assessment), the impact to Casco Bay, and ten of those are predicted to have
on the “ocean economy” has been explored for the an overall negative response to climate change within
Casco Bay region. The ocean economy—which includes the Northeast Atlantic region. The Maine Ocean and
species harvesting and processing, marine transportation, Coastal Acidification Partnership (MOCA) has been
marine construction, ship and boat building, and tourism

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 97

further working to expand the state’s understanding SOCIOECONOMIC RISK
of the effects of ocean acidification, in particular, on
commercially viable species. See Section 3: Environmental disruptions in shipping routes and delays in transit,
Exposure, Risk, and Vulnerability for further details. leading to increased costs. Likewise, a substantial
amount of coastal infrastructure—including industrial
If populations begin to collapse, growth rates shift, or or commercial shipping and storage, passenger
species distributions change, fisheries will need to alter and recreational transport facilities, as well as boat
management regimes to adapt. If supply decreases for engineering, fabrication, and assembly facilities—may
particular species, landing prices will likely increase to need to be restructured to accommodate for rising sea
compensate. Likewise, higher safety costs from more levels. Figure 2.7 shows the projected impact of sea
extreme storms, rising fuel prices, and needing to travel level rise on Portland and South Portland’s waterfronts,
further distances to reach new locations for their including inundation of the Portland piers and the areas
catch can all contribute to these rising costs. Although surrounding South Portland’s petroleum terminals.
consumers may pay higher prices, they may also switch
to alternative species (or alternative proteins), leading Tourism and Recreation – Tourism and recreation
to a decrease in revenue for these industries. There is makes up 70 percent of the gross regional product of
also the risk that a particular stock and fishery would the ocean economy in Casco Bay.136 Studies suggest
collapse altogether, resulting in loss of jobs and revenue that tourism and recreation will likely be affected both
if substitution was not readily feasible. positively and negatively due to climate change—with
more out-of-state visitors traveling to Maine to escape
Wallace et al. (2017). also highlight the equity implications increasingly uncomfortable summer weather. Besides
of changes in the harvesting and processing sector effects from crowding, tourism may be impacted by
due to climate change: more minimally-equipped, degradation of coastal infrastructure from sea level
smaller operations that have less flexibility in their rise and storm surge, beach erosion and decreased
fishing operations will not fare as well as larger, water quality (although Willard Beach and the East End
more mobile operations that have greater access to Beach are predominantly utilized by residents), as well
financial capital and substitute fisheries. This may lead as decreases in recreational fishing due to the decline in
to the consolidation and dominance of fewer, larger cold water recreational fishing species.
operations.134
IMPACT TO COMMERCIAL AREAS
Other Marine Industry – Marine transportation, which A number of commercial and industrial areas within
primarily consists of shipping and warehousing, makes Portland and South Portland are particularly vulnerable
up 18 percent of the gross regional product (GRP) of to climate impacts. In Portland, businesses and the
the Casco Bay ocean economy, followed by marine waterfront industry along Commercial Street and the
construction of port-related infrastructure (1%) and piers/wharfs are particularly vulnerable to sea level rise
ship and boat building (0.4%). Of these three sectors, and storm surge, as are the businesses and industry
marine transportation is likely to be most impacted by located in the Bayside area (Figures 2.7 and 2.8). See
climate change. As the polar ice cap continues to melt, section Section 5.2 Housing and Built Environments for
new shipping lanes in the Arctic may become increasingly further analysis of the impacts to these areas specifically.
navigable, particularly in summer months. Using the In South Portland, land surrounding the oil terminals
Northwest passage as opposed to the Panama Canal will is most vulnerable to sea level rise and storm surge in
make the trip from Asia to Europe over a week shorter, the near term, along with small portions of commercial
with Portland the first port on that course.135 With these activity in Knightville, particularly around Thomas Street
new routes come substantial new risks and uncertainties. and the South Port Marina, and along the waterfront
in Ferry Village. Any commercial activity in Ferry Village
Additionally, stronger weather patterns, sea level rise, will become increasingly vulnerable to sea level rise and
and storm surge will likely have a significant effect storm surge towards the end of the century.
on marine industries. Large storms will likely lead to
The vulnerability of these areas will likely increase
overhead, operations, and maintenance expenses for

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 98

SOCIOECONOMIC RISK TRANS

businesses and industries, making it more costly to Estimated Number ofPWoorkpersuCloammtuitoingntoCPoortlmandm(201u4)ting to Portland
operate in these specific areas. Any businesses that
choose to close or relocate outside the cities will create
repercussions for the cities’ immediate job markets,
economic vibrancy, and tax base.

In addition to the localized impacts from sea level rise Figure 5.3. Number of workers commuting to Portland. Figure
and storm surge, the increasing risk of power failures— Sosuorceu: Ur.cS.eCe:nPsuos Brutrelaaund's Plan 2030 (2017).
from high winds, storms, flooding, or high heat—will
have cascading economic impacts for businesses across PORTLAND’S PLAN | 242
the two cities. Whereas large institutions, such as Maine
Medical Center, are equipped with backup generators, will affect business continuity. Business closures, road
most businesses will face significant economic costs from closures, and interruptions in public transportation can in
IT disruptions, lost transactions, and temporary business particular lead to significant loss of income for residents
closures. This impact is particularly acute for the cities’ relying on hourly wages and/or tips. Employees who
restaurants and food industry due to the perishable work in Portland’s large food services industry may be
nature of their inventory.137 In a Massachusetts-based particularly hard hit in these scenarios.
study, 70 percent of over 900 businesses interviewed
across 20 municipalities voiced concern about the 5.2 Housing and Built
reliance of the power grid and the risk of power failures Environments
for their business.138 Businesses in Portland and South
Portland are similar in profile to those in the study, and (Economic and Social Implications)
are exposed to similar power failure risk from storms.
Extreme weather will also have a detrimental impact for The real estate market, housing affordability, and
commercial businesses reliant on pedestrian traffic. the quality of the cities’ housing stock are all likely
to be affected by climate change. Cities have begun
LIVELIHOOD VULNERABILITY documenting the ways in which property values have
Residents whose livelihoods rely on the sectors discussed already begun to shift, creating higher demand for land
above—specifically marine species harvesting, processing,
and packaging, as well as marine transportation—may
experience some of highest livelihood vulnerability tied
to a specific sector. Changes in species distribution and
abundance, as well as added operations and maintenance
costs for waterfront infrastructure may create long-term
impacts that lead to closures or consolidation. In a better
case scenario, climate change may alter the scope of
these industries (as well as tourism and recreation, and
marine construction) without leading to any job loss for
individuals working in these sectors.

More significant risks will come for small business
owners who are unable to weather severe impacts from
inventory or property loss, as well as self-employed
individuals who may lose substantial income if a
climate hazard prevents working for a period of time.
A significant number of employees within Portland and
South Portland commute into the cities on a daily basis
(Figure 5.3), increasing the risk that any road closures

ONE CLIMATE FUTURE | CLIMATE CHANGE VULNERABILITY ASSESSMENT | PG. 99